Court Opinion

ID: 9554254
Source: CourtListenerOpinion
Date Created: 2023-08-08 15:01:09.304797+00
Date Added: 2024-06-11T15:25:57.532943
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United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued April 18, 2023                  Decided August 8, 2023

                         No. 22-7010

                   ROSALIE SIMON, ET AL.,
                        APPELLEES

                              v.

REPUBLIC OF HUNGARY AND MAGYAR ALLAMVASUTAK ZRT.,
                   (MAV ZRT.),
                    APPELLANTS

            Consolidated with 22-7013, 22-7112

        Appeals from the United States District Court
                for the District of Columbia
                    (No. 1:10-cv-01770)
                    (No. 1:21-cv-01739)

    Gregory Silbert argued the cause for defendants-
appellants/cross-appellees Republic of Hungary, et al. With
him on the briefs was Konrad L. Cailteux.

     L. Marc Zell and David H. Weinstein argued the causes for
plaintiffs-appellees/cross-appellants Rosalie Simon, et al. and
                              2
Steven Heller, et al. With them on the briefs were Noam
Schreiber, Charles S. Fax, Liesel J. Schopler, and Paul G.
Gaston.

    Andrew D. Freeman and Anthony J. May were on the brief
for amicus curiae Professor Vivian Grosswald Curran in
support of plaintiffs-appellees/cross-appellants.

   Before: PILLARD and CHILDS, Circuit Judges, and
RANDOLPH, Senior Circuit Judge.

    Opinion for the Court filed by Circuit Judge PILLARD and
Circuit Judge CHILDS.

    Opinion concurring in part and dissenting in part filed by
Senior Circuit Judge RANDOLPH.

    PILLARD and CHILDS, Circuit Judges: These two
consolidated cases arise out of the Hungarian government’s
confiscation of property owned by Jews during the Holocaust.
“Nowhere was the Holocaust executed with such speed and
ferocity as it was in Hungary.” Simon v. Republic of Hungary,
812 F.3d 127, 133 (D.C. Cir. 2016) (quoting Simon, First Am.
Compl. ¶ 1 (J.A. 44)). In 1944, as World War II neared its end,
the Hungarian government implemented an accelerated
campaign to exterminate its remaining Jewish population.
Within a matter of months, the government systematically
executed over half a million Jews—roughly two-thirds of the
Jewish population in Hungary at the war’s outset. This state-
perpetrated genocidal campaign ranks among the greatest
crimes in human history.

    The questions raised by these appeals bear on whether
survivors of the Hungarian Holocaust may hale the Hungarian
government and its instrumentalities into United States courts
                               3
to answer for a subset of the wrongs they committed—namely,
their confiscation of property from victims of the Holocaust.
The plaintiffs invoke the Foreign Sovereign Immunities Act’s
expropriation exception as a means to pierce the Hungarian
state’s sovereign immunity and assert jurisdiction in federal
district court. Defendants object that the exception is
inapplicable.

     In the first of the two cases consolidated before us, Simon
v. Republic of Hungary, fourteen survivors of the Hungarian
Holocaust sue the Republic of Hungary and one of its agencies,
Magyar Államvasutak Zrt., seeking compensation for the
seizure of their property during the Holocaust. The litigation
in Simon is long running, and we have reviewed appeals in the
case twice before. In the second case, Heller v. Republic of
Hungary, two Holocaust survivors more recently sued for
compensation from Hungary for property confiscated from
their late parents and grandparents during the war.

     Cognizant of the Supreme Court’s recent holding that “a
country’s alleged taking of property from its own nationals”
generally falls outside the scope of the Foreign Sovereign
Immunities Act’s expropriation exception, Fed. Republic of
Germany v. Philipp, 141 S. Ct. 703, 708 (2021); see id. at 715,
the plaintiffs in these suits assert they were not Hungarian
nationals at the time of the takings at issue. They instead claim
that they were either stateless or Czechoslovakian nationals.
The district court dismissed the claims of the plaintiffs
asserting statelessness but concluded that most of the plaintiffs
asserting Czechoslovakian nationality could proceed.

     We largely affirm. Like the district court, we conclude
that the plaintiffs claiming statelessness—Zehava Friedman,
Vera Deutsch Danos, Steven Heller, and Charles Heller—have
not made out a recognized claim within a Foreign Sovereign
                                4
Immunities Act exception. Assuming without deciding that
those plaintiffs were de facto stateless at the time of the alleged
takings, as they claim, the plaintiffs have nevertheless failed to
identify adequate affirmative support in sources of
international law for their contention that a state’s taking of a
stateless person’s property amounts to a taking “in violation of
international law” within the meaning of the Foreign Sovereign
Immunities Act. 28 U.S.C. § 1605(a)(3). We do not foreclose
the possibility that such a takings claim might prevail if
grounded in sources of international law not before us or based
on arguments not raised here. But on this record, we affirm the
district court’s dismissal of those four plaintiffs’ claims.

     We likewise affirm the district court’s denial of the
defendants’ motions to dismiss the claims of some of the
plaintiffs asserting Czechoslovakian nationality, with a few
exceptions. The district court correctly determined that four of
those plaintiffs—Magda Kopolovich Bar-Or, Yitzhak
Pressburger, Alexander Speiser, and Moshe Perel—had
plausibly alleged they were Czechoslovakian nationals at the
time of the takings. As for the five Lebovics sisters, the district
court should have dismissed their claims, along with those of
Tzvi Zelikovitch and Ella Feuerstein Schlanger, for failure to
plausibly allege Czechoslovakian nationality. We direct that
those dismissals, however, be without prejudice to the
opportunity of any of those plaintiffs to amend in the event they
can cure the identified defects in their nationality allegations.

     In reaching this conclusion, we reject the Hungarian
defendants’ arguments that the plaintiffs are judicially
estopped from asserting Czechoslovakian nationality and that,
even assuming they were Czechoslovakian at the time of the
takings, the Foreign Sovereign Immunities Act’s treaty
exception bars their claims. We also reject the plaintiffs’
                               5
theory that Hungary’s alleged treaty violations enable the
plaintiffs to bypass the domestic takings rule.

     Hungary and its instrumentality also assert that the
plaintiffs’ claims of expropriation in violation of international
law lack the nexus to commercial activity in the United States
that the Foreign Sovereign Immunities Act requires. We
remand for the district court to make certain factual
determinations regarding that nexus element of the remaining
plaintiffs’ claims.

    All told, the claims of four Simon plaintiffs may proceed,
and an additional eight Simon plaintiffs will have the
opportunity to amend their pleadings. The district court,
however, appropriately dismissed the Heller plaintiffs’ claims.

                               I.

                               A.

     The historical events giving rise to these suits are
recounted at length in our first two opinions in the Simon
litigation, see Simon v. Republic of Hungary (Simon I), 812
F.3d 127, 132-34 (D.C. Cir. 2016), abrogated in part by Fed.
Republic of Germany v. Philipp, 141 S. Ct. 703 (2021); Simon
v. Republic of Hungary (Simon II), 911 F.3d 1172, 1176-78
(D.C. Cir. 2018), vacated, 141 S. Ct. 691 (2021) (per curiam),
as well as the district court’s Simon and Heller opinions, see
Simon v. Republic of Hungary (Simon-2021), 579 F. Supp. 3d
91, 97-99 (D.D.C. 2021); Heller v. Republic of Hungary, No.
21-cv-1739-BAH, 2022 WL 2802351, at *1-2 (D.D.C. July 18,
2022). Further background is provided here as relevant to the
disputes at issue.

    We begin with a brief account of Hungary’s evolving
borders during the early twentieth century and their
                               6
implications for the nationalities of persons living in affected
territory. Prior to World War I, the Austro-Hungarian Empire
controlled a significant share of European territory, including
parts of modern-day Hungary, Slovakia, and the Czech
Republic. At the war’s end, however, the Austro-Hungarian
Empire was dismembered into several smaller states organized
primarily along ethno-linguistic lines. The Kingdom of
Hungary, which had been part of the Austro-Hungarian
Empire, ceded approximately two-thirds of its territory to
newly created states. The territory Hungary retained is often
referred to as “Trianon Hungary,” in recognition of the treaty
that largely defined its borders: the 1920 Treaty of Trianon.
Treaty of Peace Between the Allied and Associated Powers and
Hungary arts. 27-35, June 4, 1920, S. Treaty Doc. No. 67-348
(1923) (Treaty of Trianon). In that treaty, Hungary also agreed
to recognize the independence of a new nation state,
Czechoslovakia, in an area that had comprised the northern
region of the Austro-Hungarian Empire. See id. art. 48.

     As relevant here, two post-war treaties governed the
assignment of nationalities to persons in the territories ceded
by Hungary to Czechoslovakia. First, the 1919 Treaty of St.
Germain required the newly created state of Czechoslovakia to
extend its citizenship to most Hungarian nationals who were
habitually residing in the territory that became part of
Czechoslovakia. Treaty Between the Principal Allied and
Associated Powers and Czechoslovakia art. 3, Sept. 10, 1919,
S. Treaty Doc. No. 67-348 (1923) (St. Germain Treaty). The
St. Germain Treaty also established that “[a]ll persons born in
Czecho-Slovak territory who are not born nationals of another
State shall” acquire Czechoslovakian nationality. Id. art. 6.
Second, the 1920 Treaty of Trianon included parallel
provisions granting Czechoslovakian nationality to, and
stripping Hungarian nationality from, those who had “rights of
citizenship” in the territory that became part of
                              7
Czechoslovakia, Treaty of Trianon art. 61, subject to certain
conditions and exceptions, id. arts. 62-66.

     The borders of this newly conceived Czechoslovakian
state, however, did not last. In 1938 and 1939, on the eve of
World War II in Europe, Nazi Germany and Hungary illegally
annexed parts of Czechoslovakia. Hungary thereafter sought
to re-nationalize persons living in annexed regions who had
lived there continuously from 1929 to 1939, and who had been
Hungarian citizens as of 1921. In practice, however,
“Hungarian officials imposed excessively stringent demands
for proof of Hungarian citizenship upon Jews, making it
virtually impossible for most Jewish residents of [annexed
territory] to comply, with the result that they did not acquire
Hungarian citizenship.” Bar-Shaked Decl. ¶ 62 (J.A. 1868);
see id. ¶ 61 & n.31 (J.A. 1867). Hungarian laws also prohibited
Jews from obtaining Hungarian citizenship by naturalization.
Id. ¶ 31 (J.A. 1853).

     After it became clear that they would lose the war, Nazi
Germany and Hungary “raced to complete their eradication of
the Jews before the Axis surrendered.” Simon Second Am.
Compl. (Simon SAC) ¶ 3 (J.A. 238). Winston Churchill
described Hungary’s genocidal campaign as “probably the
greatest and most horrible crime ever committed in the history
of the world.” Simon I, 812 F.3d at 132. The Axis powers
wiped out more than two-thirds of Hungary’s pre-war Jewish
population during the course of the war. Id. at 134. “The
overwhelming majority of those deaths came from the roughly
430,000 Hungarian Jews deported to Auschwitz” or other
concentration camps. Id. On November 3, 1944, the
Hungarian government declared all valuable objects owned by
Jews—except for their most personal items—part of the
national wealth of Hungary. Hungary confiscated and
liquidated much of that property.
                                8
     At the close of World War II, the Allied and Associated
Powers entered into a peace treaty with Hungary. Treaty of
Peace with Hungary, Feb. 10, 1947, 61 Stat. 2065, 41 U.N.T.S.
135 (1947 Treaty). The 1947 Treaty declared Hungary’s
annexation of Czechoslovakian territory null and void and
returned to Czechoslovakia certain regions Hungary had
illegally annexed. Id. art 1.

                               B.

     The Foreign Sovereign Immunities Act (FSIA) provides
“the sole basis for obtaining jurisdiction over a foreign state in
our courts.” Argentine Republic v. Amerada Hess Shipping
Corp., 488 U.S. 428, 434 (1989); see 28 U.S.C. § 1602 et seq.
Absent a pre-existing agreement with the United States
affecting the scope of sovereign immunity, a foreign sovereign
is generally immune, unless one of the FSIA’s enumerated
exceptions applies. See 28 U.S.C. §§ 1604, 1605-1605B,
1607; OBB Personenverkehr AG v. Sachs, 577 U.S. 27, 31
(2015).

     This case concerns the FSIA’s expropriation exception,
codified at Title 28, Section 1605(a)(3). That exception waives
foreign sovereign immunity in any case in which:

       [1] rights in property taken in violation of
       international law are in issue and [2.A.] that
       property or any property exchanged for such
       property is present in the United States in
       connection with a commercial activity carried
       on in the United States by the foreign state; or
       [2.B.] that property or any property exchanged
       for such property is owned or operated by an
       agency or instrumentality of the foreign state
                                9
       and that agency or instrumentality is engaged in
       a commercial activity in the United States.

28 U.S.C. § 1605(a)(3). Generally speaking, the exception has
two requirements: (1) the claim must put in issue “rights in
property taken in violation of international law,” and (2) there
must be an adequate connection between the defendant and
both the expropriated property and some form of commercial
activity in the United States. Id. We refer to the latter as the
commercial-activity nexus requirement.

     With respect to the first requirement, the Supreme Court
in Philipp held that “the phrase ‘rights in property taken in
violation of international law,’ as used in the FSIA’s
expropriation exception, refers to violations of the international
law of expropriation, and thereby incorporates the domestic
takings rule.” 141 S. Ct. at 715. Under the domestic takings
rule, a foreign sovereign’s taking of its own nationals’ property
is not a violation of the international law of expropriation. Id.
at 709. Philipp thus generally bars plaintiffs who were
nationals of the expropriating state at the time of the alleged
taking from invoking the expropriation exception. See id. at
715.

     The FSIA also contains a provision known as the “treaty
exception.” Simon I, 812 F.3d at 135-36; see 28 U.S.C. § 1604.
Per that provision, the FSIA’s baseline grant of immunity to
foreign sovereigns is “[s]ubject to existing international
agreements to which the United States [was] a party at the time
of enactment” of the FSIA. 28 U.S.C. § 1604. “[I]f there is a
conflict between the FSIA and such an agreement regarding the
availability of a judicial remedy against a contracting state, the
agreement prevails.” de Csepel v. Republic of Hungary (de
Csepel II), 859 F.3d 1094, 1100 (D.C. Cir. 2017) (quoting de
                             10
Csepel v. Republic of Hungary (de Csepel I), 714 F.3d 591, 601
(D.C. Cir. 2013)).

                             C.

     Two cases are consolidated before us on appeal: Simon v.
Republic of Hungary and Heller v. Republic of Hungary. The
plaintiffs in these cases—Rosalie Simon, Helen Herman,
Charlotte Weiss, Helena Weksberg, Rose Miller, Tzvi
Zelikovitch, Magda Kopolovich Bar-Or, Zehava (Olga)
Friedman, Yitzhak Pressburger, Alexander Speiser, Tibi Ram,
Moshe Perel, Vera Deutsch Danos, Ella Feuerstein Schlanger,
Steven Heller, and Charles Heller—are survivors of the
Hungarian Holocaust (collectively, Survivors).

     Many were teenagers when Magyar Államvasutak Zrt
(MÁV), the Hungarian national railway, delivered them to
concentration camps in cattle cars. Two fled abroad and one
remained in hiding and avoided deportation. The Survivors
claim to have never received compensation for the personal
property the Hungarian defendants allegedly stole from them,
often while they were being transported to concentration camps
or killing fields.

                              1.

     The Simon litigation has been ongoing for more than a
decade. The case was filed on October 20, 2010, as a putative
class action by plaintiffs Simon, Herman, Weiss, Weksberg,
Miller, Zelikovitch, Bar-Or, Friedman, Pressburger, Speiser,
Danos, Schlanger, Tibi Ram, and soon thereafter was amended
to add plaintiff Perel (collectively, the Simon Survivors or
Simon plaintiffs). Simon, Herman, Weiss, Weksberg, and
Miller are sisters, whose maiden name was Lebovics
(collectively, Lebovics sisters). The Simon Survivors filed
their complaint against the Republic of Hungary (Hungary) and
                              11
MÁV (together, the Hungarian defendants). (One other
defendant was dismissed on grounds not challenged here).

     The Hungarian defendants moved to dismiss for lack of
subject matter jurisdiction based on, inter alia, the FSIA’s
treaty exception, the Simon Survivors’ failure to allege the
elements necessary to invoke the expropriation exception, and
the political question doctrine. The district court granted the
Hungarian defendants’ motion, holding that the FSIA’s treaty
exception immunized them from suit. See Simon v. Republic
of Hungary (Simon-2014), 37 F. Supp. 3d 381, 424 (D.D.C.
2014). Because the district court deemed the treaty exception
dispositive, it declined to resolve the defendants’ alternative
grounds for dismissal. See id. at 407 n.21.

     The Simon Survivors appealed, and we reversed. In Simon
I, we held that the treaty exception did not divest the court of
jurisdiction over the case because the Simon Survivors’ action
based on common-law claims did not create an express conflict
between the treaty provision on which the Hungarian
defendants relied, Article 27 of the 1947 Treaty, and the FSIA
immunity provisions. Simon I, 812 F.3d at 140. We further
held that the expropriation exception applied to the Simon
plaintiffs’ claims that they had been deprived of property
without compensation. Id. at 132, 140-49. We concluded that
those claims put in issue property “taken in violation of
international law” for purposes of the FSIA’s expropriation
exception, because the alleged takings of property amounted to
the commission of genocide. Id. at 142 (quoting 28 U.S.C.
§ 1605(a)(3); see id. at 141-46. Additionally, we concluded
that the Simon plaintiffs’ allegations satisfied the commercial-
activity nexus of the expropriation exception. Id. at 146-49.
We remanded the matter for the district court to consider
“whether, as a matter of international comity, it should refrain
from exercising jurisdiction over th[e] [Simon plaintiffs’]
                               12
claims until the plaintiffs exhaust domestic remedies in
Hungary.” Id. at 151.

     On remand from Simon I, the Simon Survivors filed an
amended complaint, and the Hungarian defendants moved to
dismiss a second time. The defendants sought dismissal based
on, inter alia, forum non conveniens and international comity
grounds. The district court granted the Hungarian defendants’
motion to dismiss on both grounds. Simon v. Republic of
Hungary (Simon-2017), 277 F. Supp. 3d 42, 47, 62, 67 (D.D.C.
2017).

     The Simon Survivors appealed a second time. We again
reversed, holding that the district court erred in concluding that
the doctrine of forum non conveniens barred the Simon
plaintiffs’ suit and in declining statutorily secured jurisdiction
on international comity grounds. Simon II, 911 F.3d at 1176
(citing Philipp v. Fed. Republic of Germany, 894 F.3d 406
(D.C. Cir. 2018)).

    The parties then litigated a third motion to dismiss that
focused on whether the Simon plaintiffs’ claims satisfied the
expropriation    exception’s    commercial-activity     nexus
requirement. Simon v. Republic of Hungary (Simon-2020), 443
F. Supp. 3d 88, 116 (D.D.C. 2020). The district court denied
the motion and another appeal was taken in this case—this time
with the Hungarian defendants as the appellants. Id.

     In the meantime, the Supreme Court granted the
Hungarian defendants’ petition for certiorari in Simon II on the
international comity question. The Supreme Court decided this
case simultaneously with Philipp, a related FSIA case. The
Philipp Court held that “the expropriation exception is best
read as referencing the international law of expropriation rather
than of human rights.” 141 S. Ct. at 712. Philipp thus clarified
that genocidal takings do not necessarily constitute takings “in
                              13
violation of international law” for purposes of the FSIA’s
expropriation exception, id. at 715 (quoting 28 U.S.C.
§ 1605(a)(3)), thereby partially abrogating our opinion in
Simon I. Without resolving the question of international
comity on which the Court had granted certiorari in this case,
the Supreme Court issued a judgment vacating our Simon II
decision and remanded the matter for further proceedings
consistent with Philipp. Republic of Hungary v. Simon, 141 S.
Ct. 691 (2021) (per curiam). In light of the Supreme Court’s
ruling, we remanded the case to the district court for further
proceedings consistent with Philipp.

     With Simon back before the district court, the Hungarian
defendants moved, for a fourth time, to dismiss the Simon
Survivors’ claims for lack of subject matter jurisdiction under
the FSIA. The Hungarian defendants argued, inter alia, that
the domestic takings rule barred the Simon plaintiffs from
invoking the expropriation exception. They also argued that,
even if any Simon plaintiffs had been foreign nationals, the
treaty exception would divest the court of jurisdiction. In
response to the defendants’ domestic takings rule argument,
the Simon Survivors asserted that they were not Hungarian
nationals at the time of the alleged takings. They argued that,
during the relevant time period, two of the Simon Survivors
were de facto stateless and twelve were Czechoslovakian
nationals. The district court partially granted the motion, with
the outcome varying by Survivor. Simon-2021, 579 F. Supp.
3d at 140-41. The Hungarian defendants appeal and the Simon
Survivors cross-appeal.

                               2.

    That brings us to the second action in this consolidated
appeal. More than a decade after the Simon litigation began, a
separate group of survivors brought a similar lawsuit against
                              14
Hungary. The named plaintiffs, Charles Heller and Steven
Heller (together, Heller Survivors or Heller plaintiffs), are
brothers. They were toddlers in 1939, when their parents and
grandparents abandoned their businesses, personal
possessions, and homes in Hungary and fled with the brothers
to the United States. After the war, the Heller family returned
to Hungary to find other people living in their homes, operating
their businesses, and using their possessions. The Heller
Survivors do not claim to have been Czechoslovakian citizens,
nor do they claim to have acquired any non-Hungarian
nationality before the takings. Rather, they assert that they
were de facto stateless at the time of the alleged takings. Just
as it had in Simon, Hungary moved to dismiss the Hellers’
claims for lack of jurisdiction under the FSIA. Hungary argued
that the domestic takings rule barred application of the FSIA’s
expropriation exception because, according to Hungary, both
Heller plaintiffs were Hungarian nationals at the time of the
alleged takings. The district court granted Hungary’s motion
and dismissed the Heller Survivors’ claims. The brothers
appeal.

                              II.

     We begin with the Survivors’ cross-appeal in Simon and
direct appeal in Heller challenging the district court’s
dismissals of the claims of the Survivors asserting de facto
statelessness. We refer to those plaintiffs as the Trianon
Survivors. They argue that, because Hungary rendered them
de facto stateless by the time of the alleged takings, the
domestic takings rule poses no bar to their claims against
Hungary. The district court rejected that argument. It granted
the Hungarian defendants’ motions to dismiss the Trianon
Survivors’ claims as incompatible with the Supreme Court’s
ruling in Philipp. See Simon-2021, 579 F. Supp. 3d at 115-19,
140; Heller, 2022 WL 2802351, at *7-9.
                                15
     The district court reasoned that, if the conduct alleged to
have rendered the Trianon Survivors stateless also amounted to
genocide, Philipp forecloses that statelessness from triggering
the expropriation exception. Simon-2021, 579 F. Supp. 3d at
119; Heller, 2022 WL 2802351, at *8. Thus, stopping short of
deciding whether the domestic takings rule is generally
inapplicable to stateless aliens, the district court read Philipp to
bar FSIA expropriation claims by plaintiffs claiming de facto
statelessness by virtue of experiencing genocide. Simon-2021,
579 F. Supp. 3d at 119; Heller, 2022 WL 2802351, at *7
(“Whatever the merits of plaintiffs’ argument that the domestic
takings rule does not, as a general matter, reach claims by
stateless persons, . . . Philipp ‘precludes reliance on the
egregiousness or genocidal nature of expropriative conduct as
a means to escape the limitation of the domestic takings rule.’”
(quoting Simon-2021, 579 F. Supp. 3d at 115)). We review the
district court’s jurisdictional rulings on questions of law de
novo, Ivanenko v. Yanukovich, 995 F.3d 232, 236 (D.C. Cir.
2021), and factual determinations for clear error, Price v.
Socialist People’s Libyan Arab Jamahiriya, 389 F.3d 192, 197
(D.C. Cir. 2004).

     We affirm the dismissal of the Trianon Survivors’ claims,
albeit for reasons different from those of the district court. The
Supreme Court’s ruling in Philipp does not foreclose the
Trianon Survivors’ theory. That said, the Survivors have failed
to identify affirmative support in sources of international law
for their legal premise that a state’s taking of property from
stateless persons amounts to a taking “in violation of
international law” within the meaning of the FSIA, 28 U.S.C.
§ 1605(a)(3)—that is, in violation of “the international law of
expropriation,” Philipp, 141 S. Ct. at 712, 715. The Trianon
Survivors have thus failed to persuade us that their claims are
cognizable under the expropriation exception.
                               16
                               A.

     We first address the parties’ dispute over the implications
of Philipp, 141 S. Ct. 703. The Hungarian defendants argue
that the Survivors’ takings theory is “the same one that the
Supreme Court already rejected” in Philipp: “[t]hat
expropriations violate international law when they are
accompanied by egregious human-rights violations.” Hungary
Resp. & Reply Br. 27. In defendants’ view, Philipp precludes
the Survivors from relying on “the egregiousness of the human
rights abuses” inflicted by a foreign sovereign to claim
statelessness and thereby escape the limitation of the domestic
takings rule. Id. at 28; see also Simon-2021, 579 F. Supp. 3d
at 115-19; Heller, 2022 WL 2802351, at *7-9. Defendants
miss the key distinction between the Simon I theory the
Supreme Court rejected in Philipp and the Trianon Survivors’
position on remand that is now before us.

     The Trianon Survivors’ theory does not conflict with
Philipp, but heeds its guidance. Philipp holds that “the phrase
‘rights in property taken in violation of international law,’ as
used in the FSIA’s expropriation exception, refers to violations
of the international law of expropriation.” 141 S. Ct. at 715
(quoting 28 U.S.C. § 1605(a)(3)). Here is the relevant
framework as we understand it post-Philipp: The international
law of expropriation incorporates the domestic takings rule,
which treats a state’s taking of its own national’s property as a
domestic legal matter not governed by international law. See
id. at 709, 715. That rule is grounded in the traditional view
that “international law customarily concerns relations among
sovereign states, not relations between states and individuals.”
Id. at 709-10. Because “[a] domestic taking . . . d[oes] not
interfere with relations among states,” it does not “implicate[]
the international legal system” under that traditional view. Id.
at 710; see also Mezerhane v. República Bolivariana de
                               17
Venezuela, 785 F.3d 545, 551 (11th Cir. 2015). In the wake of
World War II, even as “international law increasingly came to
be seen as constraining how states interacted not just with other
states but also with individuals, including their own citizens,”
the “domestic takings rule endured” within the sphere of the
international law of expropriation. Philipp, 141 S. Ct. at 710.
Accordingly, in determining whether the expropriation
exception applies post-Philipp, courts generally must identify
a plaintiff’s nationality for purposes of the domestic takings
rule. Absent any superseding principle or rule encompassed in
the international law of expropriation, the threshold question
is: Was the victim of the alleged taking a national of the
foreign-state defendant at the time of the taking? If yes, the
domestic takings rule bars application of the FSIA’s
expropriation exception; if no, that bar is inapplicable. See id.
at 715.

     The Trianon Survivors have attempted to advance a viable
theory within the framework established by Philipp—that is,
based on an argument about their nationality at the time of the
alleged takings. They acknowledge that they were Hungarian
nationals before the war and do not claim that Hungary had
formally denationalized its Jewish population de jure by the
time of the alleged takings. They nonetheless contend the
domestic takings rule is inapplicable because Hungary had
rendered them de facto stateless for purposes of international
law before it took their property.

    To that end, the Survivors draw on a 1955 decision of the
Permanent International Court of Justice that a nation may not,
consistent with international law, confer nationality upon an
individual (at least for purposes of exercising diplomatic
protection in an international tribunal) where there is no
“genuine connection” between that individual and the state.
Nottebohm Case (Liech. v. Guat.), Judgment, 1955 I.C.J. Rep.
                              18
4, 23, 26 (Apr. 6). The Survivors claim that the inverse
principle must also be true: A state deprives an individual of
their nationality when it severs the “genuine connection”
between itself and the individual. And, according to the
Survivors, Hungary severed that requisite connection by
subjecting Hungarian Jews to systematic persecution during
the Holocaust, thus rendering the Trianon Survivors de facto
stateless for purposes of international law. See Survivors’
Reply Br. 8-12; Survivors’ Br. 18-25. Such de facto stateless
persons, they claim, are properly treated as “aliens” for
purposes of the domestic takings rule. Survivors’ Br. 18. That
theory conforms to the analytic framework established by
Philipp: It draws on international law governing nationality to
argue that the Trianon Survivors were not Hungarian nationals
at the time of the alleged takings. The Trianon Survivors’
argument faces other obstacles, as discussed below, but it does
not conflict with Philipp itself.

     The Hungarian defendants’ contrary reading of Philipp,
while not without some logical appeal, breaks down on closer
scrutiny. It is true, as the Hungarian defendants note, that the
Philipp Court rejected the plaintiffs’ attempt to rely on
international human rights law to satisfy the expropriation
exception’s “violation of international law” requirement. 141
S. Ct. at 712, 715. It follows, they reason, that expropriations
that violate international law “because of the ‘egregiousness of
the human rights abuses’” involved cannot give rise to a viable
takings claim for purposes of the FSIA’s expropriation
exception. Hungary Resp. & Reply Br. 28 (quoting Survivors’
Br. 23). Because the Trianon Survivors rely on Hungary’s
genocidal acts during the Holocaust (i.e., violations of
international human rights law) as the basis for their loss of
nationality, the Hungarian defendants contend that Philipp
forecloses their theory. See id. at 27-28; see also Simon-2021,
579 F. Supp. 3d at 118.
                               19
      That reading of Philipp suffers from two principal flaws.
First, it is irreconcilable with the remand in Philipp. The
Supreme Court expressly reserved judgment on the plaintiffs’
alternative theory that Germany’s alleged taking was “not
subject to the domestic takings rule because the [plaintiffs]
were not German nationals at the time of the transaction,” and
remanded for the district court to consider that argument in the
first instance. Philipp, 141 S. Ct. at 715-16. Critically, the
Philipp plaintiffs’ only theory as to why they were not German
nationals at the time of the alleged takings was materially
identical to the Trianon Survivors’ nationality argument here:
They argued that “Jews may be deemed aliens of their
respective countries during the Holocaust because they were
not treated as citizens.” Resp. Br. 15 n.5, Philipp, 141 S. Ct.
703 (No. 19-351); see also id. at 27-28. As counsel for the
Philipp plaintiffs stated during oral argument, their theory was
that “German governmental treatment of German Jews in the
1930s,” i.e., the same treatment that they argued amounted to
genocide, “transgress[ed] th[e] nationality line.” Oral Arg. Tr.
68:1-4, Philipp, 141 S. Ct. 703 (2021) (No. 19-351). When the
Supreme Court chose to remand the Philipp plaintiffs’ claims,
it knew that the relevant conduct that could divest the plaintiffs
of their nationality was part and parcel of the genocidal acts
that they had claimed violated international human rights law.
If the Court’s reasoning in Philipp foreclosed that argument,
there would have been no reason to remand.

     Second, the Hungarian defendants’ reasoning errs in
treating the limits Philipp imposed on the legal basis of an
expropriation actionable under the FSIA as also circumscribing
the historical facts germane to a claim under the expropriation
exception. Philipp clarified that “the expropriation exception
is best read as referencing the international law of
expropriation rather than of human rights.” 141 S. Ct. at 712.
Accordingly, “[w]e do not look to the law of genocide to
                              20
determine if we have jurisdiction over [a plaintiff’s] property
claims. We look to the law of property.” Id. That ruling barred
the plaintiffs from relying on the law of genocide to avoid the
domestic takings rule, which the Court viewed as an integral
principle of the international law of expropriation. See id. at
709-13, 715. What Philipp did not do, however, is limit the
underlying facts a court may consider in identifying whether
the expropriation exception applies or the domestic takings rule
is a bar. Philipp did not opine on, let alone foreclose, the
possibility that conduct that could give rise to a claim of
genocide might also bear on the nationality inquiry for
purposes of the expropriation exception or the domestic takings
rule. Rather, Philipp left open for lower courts to resolve what
conduct is relevant to the nationality inquiry. See id. at 716.
We thus reject the view that Philipp preempts the Trianon
Survivors’ takings theory.

                              B.

    The Trianon Survivors’ invocation of the expropriation
exception nevertheless fails for an independent reason: Even
assuming the Trianon Survivors were de facto stateless at the
time of the alleged takings, the Survivors have not mustered
adequate support for their contention that a state’s taking of a
de facto stateless person’s property violates the international
law of expropriation.

     Our inquiry regarding the rights of de facto stateless
persons is governed by the customary international law of
expropriation. That body of law determines whether an alleged
taking violates “international law” within the meaning of the
FSIA’s expropriation exception where, as here, the plaintiffs
do not rely on an express international agreement. See, e.g.,
Helmerich & Payne Int’l Drilling Co. v. Bolivarian Republic
of Venezuela (Helmerich II), 743 F. App’x 442, 449 (2018)
                               21
(citing Restatement (Third) of Foreign Relations Law § 102(1)
(Am. L. Inst. 1987) (Third Restatement)); Beierwaltes v.
L’Office Federale de la Culture de la Confederation Suisse,
999 F.3d 808, 821 (2d Cir. 2021). Customary international law
is the “general and consistent practice of states followed by
them from a sense of legal obligation.” Third Restatement
§ 102(2). To demonstrate a taking in violation of international
law for purposes of the FSIA’s expropriation exception, the
Survivors must show that their legal theory “has in fact
crystallized into an international norm that bears the heft of
customary law.” Helmerich II, 743 F. App’x at 449.

     To support their theory that a state’s taking of a de facto
stateless person’s property violates the international law of
expropriation, the Survivors principally rely on the Second
Restatement of Foreign Relations Law. As the Restatement in
effect when Congress enacted the FSIA, that source bears
authoritative weight in interpreting the Act. See Philipp, 141
S. Ct. at 712 (recognizing “the [Court’s] consistent practice of
interpreting the FSIA in keeping with ‘international law at the
time of the FSIA’s enactment’ and looking to the contemporary
Restatement for guidance” (quoting Permanent Mission of
India to United Nations v. City of New York, 551 U.S. 193, 199-
200 (2007))). The Survivors point to Section 185 of the Second
Restatement, which identifies a “taking by a state of property
of an alien” as “wrongful under international law” when certain
conditions are met. Restatement (Second) of Foreign Relations
Law § 185 (Am. L. Inst. 1965) (Second Restatement). And
they emphasize that Section 171 establishes that the term
“alien” encompasses both foreign nationals and stateless
persons “for purposes of the responsibility of a state for injury”
to an individual. Id. § 171.

   Notably, however, Section 175 of the Second Restatement
makes clear that stateless persons are “without remedy” under
                               22
international law for takings claims against an expropriating
state, with certain exceptions. See id. § 175 & cmt. d. Section
175 provides:

       The responsibility of [a] state under
       international law for an injury to an alien cannot
       be invoked directly by the alien against the state
       except as provided by
         (a) the law of the state,
         (b) international agreement, or
         (c) agreement between the state and the alien.

Id. § 175. And the lack of any remedy under customary
international law for a stateless alien is spelled out in Comment
(d) to that section:

       d. Stateless aliens. Under traditional principles
       of international law, a state, being responsible
       only to other states, could not be responsible to
       anyone for an injury to a stateless alien. Under
       the rule stated in this Section, a stateless alien
       may himself assert the responsibility of a state
       in those situations where an alien who is a
       national of another state may do so. However,
       in those situations not covered by the rule stated
       in this Section or by an international agreement
       providing some other remedy, a stateless alien
       is without remedy, since there is no state with
       standing to espouse his claim.

Id. § 175 cmt. d; see also id. § 174 cmt. b (“[P]rocedures
allowing persons to proceed against states . . . are unavailable
except under the limited conditions specified in § 175, and,
espousal by the state of nationality continues to be generally
necessary for the effective assertion of an international
                               23
claim.”). In their briefing, the Survivors identify no Hungarian
law, international agreement, or agreement between Hungary
and the Trianon Survivors relevant to section 175 of the Second
Restatement. Tellingly, after the Hungarian defendants
pointed out the limits set forth in section 175 on when a
stateless person has a remedy, see Hungary Resp. & Reply Br.
26-27, the Survivors abandoned reliance on that section in their
reply and failed to explain why the defendants’ point was not
fatal to their theory, see Survivors’ Reply Br. 2-12.

     The secondary sources that the Survivors cite likewise fail
to address that issue. To the extent those sources are helpful,
they merely accord with the view that stateless persons are
generally treated as aliens or non-nationals under state
domestic laws. See Marc Vishniak, The Legal Status of
Stateless Persons, in 6 Jews and the Post-War World 37
(Abraham G. Duker ed., 1945); Eric Fripp, Nationality and
Statelessness in the International Law of Refugee Status
§ 5.105 (2016).

     The Survivors have thus failed to persuade us that a state’s
taking of a de facto stateless person’s property violates the
customary international law of expropriation. To be clear, we
do not foreclose the possibility that such support exists in
sources of international law not before us in this case or based
on arguments not advanced here. We note that the Survivors
nowhere argue in their briefing that a state’s taking of a
stateless person’s property may violate the international law of
expropriation even if stateless persons are “without remedy”
under international law for such violation, Second Restatement
§ 175 cmt. d. At oral argument, the Survivors for the first time
implied as much when, in response to probing from the bench
on the point, they contended that the FSIA’s expropriation
exception itself provides the necessary remedy for
expropriations from stateless persons in violation of
                                24
international law. See Oral Arg. 37:30-38:50, 41:58-42:25,
42:40-43:40. Generally, however, “arguments raised for the
first time at oral argument are forfeited.” Physicians for Soc.
Resp. v. Wheeler, 956 F.3d 634, 647 (D.C. Cir. 2020) (quoting
United States ex rel. Davis v. District of Columbia, 793 F.3d
120, 127 (D.C. Cir. 2015)). We accordingly decline to reach
that late-raised argument and take no position here on its
potential merit.

       Our holding is more limited: On this record, the
Survivors have not demonstrated that their legal theory—that
a state’s taking of a de facto stateless person’s property violates
the international law of expropriation—has jelled into a
binding rule of customary international law. Because the
Survivors have therefore failed to show that the alleged seizure
of the Trianon Survivors’ property amounts to a “violation of
international law” for purposes of the FSIA’s expropriation
exception, 28 U.S.C. § 1605(a)(3), we affirm the district
court’s dismissal of their claims.

                               III.

     Next, we address the parties’ challenges to the district
court’s partial denial of the defendants’ motion to dismiss the
claims of the Survivors who assert that they were
Czechoslovakian nationals at the time of the alleged takings.
We refer to those plaintiffs as the Czechoslovakian Territory
Survivors, as they each allege that they were either born or
raised in Czechoslovakian territory. The district court denied
the defendants’ motion to dismiss the claims of nine of the
Czechoslovakian Territory Survivors—namely, Magda
Kopolovich Bar-Or, Yitzhak Pressburger, Alexander Speiser,
Moshe Perel, and the five Lebovics sisters. See Simon-2021,
579 F. Supp. 3d at 131-35, 140-41. The court concluded that
they had plausibly alleged Czechoslovakian nationality,
                              25
thereby bringing their claims outside the scope of the domestic
takings rule. See id. at 131-35. However, the court dismissed
the claims of one of the Czechoslovakian Territory Survivors
(Ze’ev Tibi Ram) without prejudice, and the claims of two
(Tzvi Zelikovitch and Ella Feuerstein Schlanger) with
prejudice. See id. at 140. Because those plaintiffs had failed
to adequately allege non-Hungarian nationality at the time of
the alleged takings, the court reasoned, the domestic takings
rule barred application of the FSIA’s expropriation exception
to their claims. See id. at 120-21, 135-36, 140.

     The Hungarian defendants appeal the district court’s
denial of their motion as to the nine non-dismissed plaintiffs’
claims. They argue that judicial estoppel precludes the
Survivors from denying their Hungarian nationality at this
stage in the litigation. The defendants further claim that the
district court applied the wrong pleading standard in
adjudicating their motion to dismiss the Czechoslovakian
Territory Survivors’ claims. And, in the alternative, they claim
the Survivors’ pleadings fall short even under the standard the
district court applied.

     The Survivors cross-appeal the district court’s dismissal
with prejudice of Zelikovitch and Schlanger’s claims. They
assert that the district court erroneously concluded that
Zelikovitch and Schlanger had not plausibly alleged
Czechoslovakian nationality at the time of the alleged takings.
Neither party appeals the dismissal without prejudice of Ze’ev
Tibi Ram’s claim.

     We largely affirm. We reject the Hungarian defendants’
threshold arguments regarding judicial estoppel and the
pleading standard for FSIA claims. Applying the same
plausible-pleading standard that the district court applied, we
affirm the court’s disposition of the Czechoslovakian Territory
                                26
Survivors’ claims, except that we direct the district court to
convert its allowance of the claims of the Lebovics sisters to
proceed and its dismissal of the claims of Zelikovitch and
Schlanger to dismissals without prejudice so those plaintiffs
may seek to cure the defects in their nationality allegations.

                                A.

     We first address the Hungarian defendants’ argument that
judicial estoppel bars the Czechoslovakian Territory Survivors
from claiming Czechoslovakian nationality. The Hungarian
defendants contend that in Simon I the Survivors asserted they
were Hungarian nationals to avoid application of the FSIA’s
treaty exception, and thus cannot now deny Hungarian
nationality in relation to the expropriation exception. The
district court determined that the “defendants’ judicial estoppel
argument fails because defendants [did] not clearly show that
the Simon I court relied on plaintiffs’ representations of
nationality in an outcome-determinative fashion.” Simon-
2021, 579 F. Supp. 3d at 127. We review the district court’s
decision to not invoke judicial estoppel for abuse of discretion.
See Montgomery v. IRS, 40 F.4th 702, 709 (D.C. Cir. 2022);
Temple Univ. Hosp., Inc. v. NLRB, 929 F.3d 729, 734 (D.C.
Cir. 2019).

      Judicial estoppel prevents a party from obtaining an
unfair advantage by “prevailing in one phase of a case on an
argument and then relying on a contradictory argument to
prevail in another phase.” New Hampshire v. Maine, 532 U.S.
742, 749 (2001) (quoting Pegram v. Herdrich, 530 U.S. 211,
227 n.8 (2000)). Courts invoke judicial estoppel at their
discretion to protect the integrity of the judicial process. Id. at
749-50. In evaluating whether to apply the doctrine of judicial
estoppel, courts consider: “(1) whether the party’s later
position is ‘clearly inconsistent’ with its earlier position; (2)
                                27
‘whether the party has succeeded in persuading a court to
accept that party’s earlier position, so that judicial acceptance
of an inconsistent position in a later proceeding would create
the perception that either the first or the second court was
misled’; and (3) ‘whether the party seeking to assert an
inconsistent position would derive an unfair advantage or
impose an unfair detriment on the opposing party if not
estopped.’” Temple Univ. Hosp., 929 F.3d at 733 (quoting New
Hampshire, 532 U.S. at 750-51). The three factors are not a
formulaic test. See New Hampshire, 532 U.S. at 751. Rather,
they serve as guideposts to determining whether the “balance
of equities” weighs in favor of invoking the doctrine in a given
case. Id.

     Applying those principles, we conclude the district court
exercised its sound discretion in holding that the balance of
equities tilts against applying judicial estoppel here. To start,
the first factor—whether a party’s later position is “clearly
inconsistent” with the earlier position on which it prevailed,
id.—does not favor the Hungarian defendants. In Simon I, the
parties did not litigate the question of those plaintiffs’
nationality in relation to the treaty exception—the relevant
legal issue on which the plaintiffs prevailed. See 812 F.3d at
135-40. And, while one sentence of the plaintiffs’ reply brief
in Simon I implied that they were Hungarian nationals, other
portions of the plaintiffs’ Simon I briefing ran expressly
counter to that view. For instance, in arguing that the domestic
takings rule did not bar their suit, the plaintiffs emphasized that
they were “Hungarian nationals or citizens in name only, not
substance, as they were systematically deprived of the most
fundamental rights to which a state’s nationals and citizens are
entitled, including the right to exist.” Pls.’ Reply Br. 11, Simon
I, 812 F.3d 127 (D.C. Cir. 2016) (No. 14-7082), 2014 WL
6603413, at *11 (emphasis added). In other words, the
plaintiffs affirmatively argued in their Simon I briefing that
                               28
they were substantively stripped of Hungarian nationality.
That assertion accords, rather than conflicts, with the
Survivors’ current denial of their Hungarian nationality. Read
in full, the plaintiffs’ briefing in Simon I thus falls short of
advancing a “clearly inconsistent” position. New Hampshire,
532 U.S. at 751; see also id. (explaining judicial estoppel
targets “intentional self-contradiction” (quoting Scarano v.
Cent. R. Co. of N.J., 203 F.2d 510, 513 (3d Cir. 1953))).

     The district court likewise permissibly weighed the second
factor—whether the party “succeeded in persuading a court to
accept that party’s earlier position,” id. at 750—against judicial
estoppel here, see Simon-2021, 579 F. Supp. 3d at 127. As
noted, the Simon plaintiffs made only an implicit reference to
their nationality in relation to the treaty exception in their
previous briefing. See Pls.’ Br. at 11-26, Simon I, 812 F.3d 127
(D.C. Cir. 2016) (No. 14-7082), 2014 WL 5035235, at *11-26;
Pls.’ Reply Br. 3, Simon I, 812 F.3d 127 (D.C. Cir. 2016) (No.
14-7082), 2014 WL 6603413, at *3; cf. Oral Arg. Tr. 4:20-5:2,
Simon I, 812 F.3d 127 (D.C. Cir. 2016)). And we had no
occasion in Simon I to determine the plaintiffs’ nationality,
given our holding that the treaty provision the defendants
invoked as the exclusive remedy for Hungarian nationals was
not in any event exclusive. 812 F.3d at 140. On an issue
neither contested nor decided in Simon I, our assumption then
that the plaintiffs were Hungarian nationals and our references
to them as such in analyzing the treaty exception are not
particularly weighty. See id. at 136-40. The Simon plaintiffs
thus did not in any meaningful sense “succeed[] in persuading”
us in Simon I that they were Hungarian nationals. New
Hampshire, 532 U.S. at 750.

    Finally, the third factor—the degree to which the party
seeking to assert an inconsistent position will derive an unfair
advantage if not estopped, id. at 751—fails to tip the scales in
                              29
favor of estoppel for similar reasons. Given that in Simon I the
plaintiffs did not affirmatively persuade us of their Hungarian
nationality and, moreover, expressly denied legally effective
Hungarian nationality in portions of their briefing, any
unfairness caused by declining to invoke estoppel is, at most,
slight. Additionally, while a party’s inconsistent position need
not be a “but-for cause of the first tribunal’s decision” to
warrant estoppel, Temple Univ. Hosp., 929 F.3d at 735, a court
may consider the degree to which the party’s representation
influenced the prior ruling in determining what unfairness, if
any, would result from declining to invoke estoppel. As
discussed further in Part V, infra, our treaty-exception ruling
in Simon I did not turn on the plaintiffs’ nationality. The
district court permissibly weighed that consideration against
the Hungarian defendants’ request. See Simon-2021, 579 F.
Supp. 3d at 127.

     We also conclude that the Czechoslovakian Territory
Survivors adequately preserved their claim of Czechoslovakian
nationality. But see Op. Dissenting in Part, at 5. This case is
unlike Philipp v. Stiftung Preussischer Kulturbesitz, No. 22-
7126, – F.4th –, 2023 WL 4536152 (D.C. Cir. July 14, 2023)
(per curiam), in which we held the plaintiffs failed to preserve
a claim of non-German nationality. Id. at *2. The operative
complaint in Philipp alleged that two of the individual
members of the plaintiff consortium fled Germany for the
Netherlands, see Second Am. Compl. ¶ 170, Philipp v. Stiftung
Preussischer Kulturbesitz, No. 1:15-cv-00266-CKK, (D.D.C.
Sept. 10, 2021), ECF No. 62, but plaintiffs never intimated
until their case reached the Supreme Court that they had
thereby become nationals of the Netherlands or of any other
state. We accordingly affirmed the district court’s holding that
any such claim had not been preserved.
                                30
     Here, in contrast, plaintiffs Bar-Or, Pressburger, Speiser,
and Perel each plausibly alleged the minimum requirements for
Czechoslovakian nationality in the first amended complaint in
2011, see Simon First Am. Compl. ¶¶ 21, 38, 40, 80 (J.A. 104,
108, 109, 118)—allegations they retained in the second
amended (currently operative) complaint, and that the district
court and we deem adequate to bring their claim within the
FSIA expropriation exception. See infra pp. 38-39; Simon-
2021, 579 F. Supp. 3d at 140. Consistent with those
allegations, the Czechoslovakian Territory Survivors insisted
in their earliest responsive filing in the district court that “not
all of the plaintiffs were considered Hungarian citizens when
they were deported by Defendants,” as many of the deported
Jews were “citizens of Rumania, Poland and numerous other
neighboring areas.” Pls.’ Opp’n 3, 17, Simon v. Republic of
Hungary, No. 1:10-cv-01770-BAH (D.D.C. May 6, 2011),
ECF No. 24. And, in their brief to us in Simon I, they described
themselves as “Jewish Holocaust survivors who, on the
threshold of World War II, lived within today’s Hungarian
borders or in territory annexed by Hungary in 1938 after
Czechoslovakia’s dismemberment.” Pls.’ Br. 2, Simon I, 812
F.3d 127 (D.C. Cir. 2016) (No. 14-7082), 2014 WL 5035235,
at *2 (emphasis added). To be sure, the point could have been
more distinctly preserved throughout. But, like the district
court, see Simon-2021, 579 F. Supp. 3d at 123-24, 127-29, we
hold it adequately preserved.

     With this full picture of the equities in view, we conclude
the district court acted within its sound discretion to deny the
Hungarian defendants’ request to judicially estop the
Czechoslovakian Territory Survivors from asserting
Czechoslovakian nationality at this stage in the litigation.
                               31
                               B.

     We turn next to the Hungarian defendants’ assertion that
the district court applied the wrong standard to their motion to
dismiss the Czechoslovakian Territory Survivors’ claims under
the expropriation exception. According to the Hungarian
defendants, the Supreme Court’s decision in Bolivarian
Republic of Venezuela v. Helmerich & Payne Int’l Drilling Co.
(Helmerich), 581 U.S. 170 (2017), “raised the bar to establish
jurisdiction under the FSIA,” because, they argue, it displaced
for FSIA claims the ordinary plausible-pleading standard
otherwise applicable on a motion to dismiss. Hungary Br. 20;
see also id. at 20-21. The Survivors reject that argument as
misconstruing Helmerich. They argue that, in view of
sovereign nations’ general immunity from suit, Helmerich held
inapplicable under the FSIA only the low jurisdictional
threshold of Bell v. Hood, 327 U.S. 678 (1946). In other words,
Helmerich did not make an exception to the ordinary pleading
requirements of Rule 8(a) as interpreted in Bell Atlantic Corp.
v. Twombly, 550 U.S. 544 (2007), and Ashcroft v. Iqbal, 556
U.S. 662 (2009). To establish federal question jurisdiction
under 28 U.S.C. § 1331, Bell v. Hood merely requires a legally
nonfrivolous claim, whereas Helmerich held that plaintiffs
must state a legally valid claim as a basis for jurisdiction under
the FSIA. We hold that the district court correctly applied the
ordinary plausible-pleading standard we have consistently
applied in FSIA cases, including Simon I, which the Supreme
Court’s decision in Helmerich left undisturbed.

     As a threshold matter, the Survivors claim the Hungarian
defendants forfeited their Helmerich argument. Assuming that
objections to subject matter jurisdiction under the FSIA are
forfeitable, we exercise our discretion to reach the Hungarian
defendants’ Helmerich argument. We typically review
forfeited arguments “only in exceptional circumstances, as, for
                               32
example, in cases involving uncertainty in the law [or] novel,
important, and recurring questions of federal law.” Flynn v.
Comm’r, 269 F.3d 1064, 1069 (D.C. Cir. 2001). This case
presents such circumstances.       Helmerich arguably has
introduced “uncertainty in the law” governing motions to
dismiss on foreign sovereign immunity grounds, and the
Hungarian defendants’ novel heightened pleading theory is
both important and likely to recur in future FSIA cases. Id.
The question is squarely presented and amply briefed in this
case, and we would be remiss if we did not resolve it.

    We conclude Helmerich did not disturb the plausible-
pleading standard that we employed in Simon I. Rather,
Helmerich rejected the “nonfrivolous-argument standard” that
we had applied to the legal theory on which a plaintiff might
depend to establish jurisdiction under the FSIA in Helmerich I.
Helmerich, 581 U.S. at 187; see id. at 173-74, 177-83;
Helmerich & Payne Int’l Drilling Co. v. Bolivarian Republic
of Venezuela (Helmerich I), 784 F.3d 804, 811-12 (D.C. Cir.
2015).

     In our vacated Helmerich decision, we held that we would
grant a motion “on the grounds that the plaintiff has failed to
plead a ‘taking in violation of international law’ or has no
‘rights in property . . . in issue’ only if the claims are ‘wholly
insubstantial or frivolous.’” 784 F.3d at 812 (quoting Agudas
Chasidei Chabad of U.S. v. Russian Fed’n, 528 F.3d 934, 943
(D.C. Cir. 2008)); see also id. at 811 (quoting Bell, 327 U.S. at
682). The legal issue before us was whether a Venezuela-
incorporated, wholly owned subsidiary of a U.S. company
could invoke the FSIA’s expropriation exception to sue the
Venezuelan government. See id. at 812. Venezuela argued that
the suit was barred because the subsidiary should be treated as
a Venezuelan national, bringing the alleged taking within the
domestic takings rule’s scope. Id. The plaintiffs countered that
                              33
international law recognizes an exception to that rule when a
sovereign unreasonably discriminates based on a company
shareholder’s nationality in expropriating that company’s
property. Id. at 812-13. The parties also disputed whether the
U.S. parent company had property rights in the subsidiary that
were cognizable under international law. Id. at 814. We
acknowledged that the plaintiffs had advanced novel legal
theories to support their invocation of the FSIA’s expropriation
exception, but in denying defendants’ motion to dismiss for
lack of jurisdiction we did not decide whether those theories
were valid. See id. at 812-16. Instead, we denied the motion
because we thought it sufficed that the plaintiffs had “asserted
a non-frivolous international expropriation claim” and had “put
[their] rights in property in issue in a non-frivolous way.” Id.
at 812 (quoting Chabad, 528 F.3d at 941); see id. at 813, 816.

     The Supreme Court vacated that ruling. It held that “a
party’s nonfrivolous, but ultimately incorrect, argument that
property was taken in violation of international law is
insufficient to confer jurisdiction” under the FSIA. Helmerich,
581 U.S. at 174. Rather, the complaint must make “a legally
valid claim that a certain kind of right is at issue
(property rights) and that the relevant property was taken in a
certain way (in violation of international law).” Id. (emphasis
omitted). The Supreme Court took issue with our decision to
confirm the district court’s jurisdiction because “the
plaintiffs might have such a claim,” requiring instead that
courts decide at the jurisdictional threshold whether plaintiffs
actually have a claim that is legally cognizable under the FSIA.
Id. at 177. The Court found no support in the text, history, and
purpose of the FSIA for permitting courts to exercise
jurisdiction over a foreign sovereign “where there is a
nonfrivolous but ultimately incorrect argument that the taking
violates international law.” Id. at 182; see id. at 176-83, 187.
                                34
     In holding the nonfrivolous-argument standard
inapplicable to the FSIA, Helmerich did not alter the plausible-
pleading standard. The Hungarian defendants conflate the
distinct issues of the validity of a legal theory and the standard
for assessing factual allegations in a complaint. As the
Supreme Court has made clear in other contexts, the plausible-
pleading standard clarified in Twombly and Iqbal “concern[s]
the factual allegations a complaint must contain to survive a
motion to dismiss,” Johnson v. City of Shelby, 574 U.S. 10, 12
(2014) (per curiam), not the degree to which plaintiffs’ legal
theories must be correct on their merits. Helmerich thus did
not create a heightened pleading standard. Contrary to the
Hungarian defendants’ argument, nothing in Helmerich affects
the familiar standard we have consistently applied to review
the plaintiffs’ factual allegations in FSIA cases like Simon I.

    Indeed, prior to Helmerich, it was our longstanding
practice to apply the plausible-pleading standard to resolve
motions to dismiss on FSIA grounds where a defendant
challenges only the legal sufficiency of a plaintiff’s allegations.
See, e.g., Price, 389 F.3d at 194, 197; Rong v. Liaoning
Province Gov’t, 452 F.3d 883, 885 n.2, 888 (D.C. Cir. 2006);
Simon I, 812 F.3d at 147. And our rulings following Helmerich
have, correctly, continued to apply the plausible-pleading
standard in that context. See, e.g., Ivanenko, 995 F.3d at 236;
Valambhia v. United Republic of Tanzania, 964 F.3d 1135,
1139 (D.C. Cir. 2020); Schubarth v. Fed. Republic of
Germany, 891 F.3d 392, 398-99 (D.C. Cir. 2018); EIG Energy
Fund XIV, L.P. v. Petroleo Brasileiro, S.A., 894 F.3d 339, 345
(D.C. Cir. 2018).

     Finding no support in our precedent, the Hungarian
defendants turn to Rukoro v. Federal Republic of Germany,
976 F.3d 218 (2d Cir. 2020). But Rukoro does not bind us, and
to the extent it is inconsistent with our approach, we believe it
                               35
is incorrect. Rukoro reads Helmerich’s requirement of “a
legally valid claim” to have, sub silentio, adopted for purposes
of FSIA claims a heightened standard of pleading, beyond the
Rule 8(a) “plausibility standard” as clarified in Twombly and
Iqbal. Id. at 224-25. In so doing, Rukoro erroneously implies
that Helmerich’s requirement of a legally valid (not just
nonfrivolous) legal theory equates to a more demanding
standard of pleading. See id. at 225 (“Such allegations may
satisfy a plausibility standard, but not a valid argument
standard.”). The Second Circuit in Rukoro acknowledged that
it thereby departed from our approach in Simon I—a departure
it viewed as required by the Supreme Court’s ensuing decision
in Helmerich. Id. (citing Simon I, 812 F.3d at 147). Because
we conclude Helmerich left the generally applicable plausible-
pleading standard undisturbed, we affirm the district court’s
adherence to it.

     In short, we hold that the plausible-pleading standard that
we applied in Simon I remains good law post-Helmerich. The
Hungarian defendants challenge the adequacy of the
Czechoslovakian Territory Survivors’ factual allegations—and
specifically, whether the pleadings plausibly allege facts that
support their alleged Czechoslovakian nationality, and hence
that their property was taken “in violation of international law.”
28 U.S.C. § 1605(a)(3). The district court was correct to apply
the plausible-pleading standard articulated in Simon I. We
must adhere to that same standard in our de novo review of the
Survivors’ nationality allegations, to which we now turn.

                               C.

     Although the Survivors who claim statelessness cannot
prevail, we conclude that a subset of the Survivors who assert
Czechoslovakian nationality are entitled to proceed in the
litigation.
                               36
     Recall that the district court denied the defendants’ motion
to dismiss the claims of nine of the Czechoslovakian Territory
Survivors: Magda Kopolovich Bar-Or, Yitzhak Pressburger,
Alexander Speiser, Moshe Perel, and the five Lebovics sisters.
See Simon-2021, 579 F. Supp. 3d at 131-35, 140-41. The court
dismissed the claims of one of the Czechoslovakian Territory
Survivors (Ze’ev Tibi Ram) without prejudice to his right to
replead and dismissed the claims of the other two (Tzvi
Zelikovitch and Ella Feuerstein Schlanger) with prejudice. See
id. at 140.

     The Hungarian defendants challenge the district court’s
decision not to dismiss nine of the Czechoslovakian Territory
Survivors’ claims. They argue that, even assuming the
plausible-pleading standard applies, those Survivors failed to
adequately allege that they were Czechoslovakian nationals at
the time of the takings. Absent such allegations, they contend,
the Survivors have not pleaded that their property was “taken
in violation of international law” for purposes of the FSIA’s
expropriation exception. 28 U.S.C. § 1605(a)(3).

     On cross-appeal, the Survivors challenge the district
court’s dismissal of Schlanger and Zelikovitch’s claims for
failing to plausibly allege Czechoslovakian nationality. They
argue that the district court overlooked relevant allegations and
filings in the record that demonstrate both were
Czechoslovakian nationals at the time of the takings.

     We review de novo the district court’s jurisdictional
rulings on the adequacy of the Czechoslovakian Territory
Survivors’ allegations under the plausible-pleading standard.
See Schubarth, 891 F.3d at 398. We conclude that four of the
Czechoslovakian Territory Survivors—Bar-Or, Pressburger,
Speiser, and Perel—are entitled to proceed in the litigation.
However, we direct the district court to dismiss the claims of
                               37
the five Lebovics sisters, Zelikovitch, and Schlanger without
prejudice.

                               1.

     We begin by deciding which body of law governs the
question: international or domestic law. “[W]hile it is for each
state to determine under its own law who are its nationals, such
law must be recognised by other states only ‘in so far as it is
consistent with international conventions, international
custom, and the principles of law generally recognised with
regard to nationality.’” 1 Oppenheim’s International Law
§ 378 (Sir Robert Jennings & Sir Arthur Watts eds., 9th ed.
1996) (quoting Hague Convention of 1930 on Certain
Questions Relating to the Conflict of Nationality Laws art. I,
Apr. 12, 1930, 179 L.N.T.S. 89); see also Oliver Dörr,
Nationality, Max Planck Encyclopedias of International Law
¶ 4 (recognizing that “international law limits [the] discretion”
of a state to “determine under its own law who are its nationals”
for purposes of “acceptance on the international plane”);
Nottebohm Case, 1955 I.C.J. Rep. at 23 (“[A] State cannot
claim that the rules it has . . . laid down are entitled to
recognition by another State unless it has acted in conformity
with [international principles governing nationality].”).

     As relevant here, treaties executed at the close of World
War I established international obligations regarding the
nationality of persons living in territory transferred from the
Austro-Hungarian Empire to the newly created
Czechoslovakian state. The 1919 Treaty of St. Germain,
executed between the Allied and Associated Powers and
Czechoslovakia, imposed international obligations on
Czechoslovakia to confer nationality on certain persons within
Czechoslovakia’s new borders. See St. Germain Treaty arts. 3-
6. The 1920 Treaty of Trianon, which ended World War I
                               38
hostilities between Hungary and the Allied and Associated
Powers, also established rules to govern the nationalities of
individuals living in the newly formed Czechoslovakian state.
See Treaty of Trianon arts. 61-66, 213.

     Accordingly, in this circumstance, we look first to
international law to determine the Survivors’ nationality status.
Czechoslovakian and Hungarian state law governing
nationality remains relevant, but only “in so far as it is
consistent with” the international legal obligations set forth in
the Treaty of St. Germain and the Treaty of Trianon. 1
Oppenheim’s International Law § 378 (quoting Hague
Convention of 1930 art. I).

                               2.

     Within that framework, we examine whether the Survivors
have plausibly alleged Czechoslovakian nationality, thereby
bringing their claims outside the scope of the domestic takings
rule. Because the Hungarian defendants’ position “amounts to
a challenge to the legal sufficiency of the allegations . . . we
must thus ‘decide de novo whether the alleged jurisdictional
facts are sufficient to divest the foreign sovereign of its
immunity.” Mwani v. bin Laden, 417 F.3d 1, 15-16 (D.C. Cir.
2005) (formatting modified) (quoting Price, 389 F.3d at 197).
Dismissal is warranted only if no plausible inferences can be
drawn from the facts alleged that, if proven, would bring
plaintiffs’ claims within an exception to sovereign immunity
under the FSIA. Schubarth, 891 F.3d at 398. We must accept
as true the allegations in the complaint and grant the survivors
the benefit of all reasonable inferences that can be derived from
the facts alleged. See id. at 400-01.

    The district court observed that Bar-Or, Pressburger,
Speiser, and Perel, each alleged that in the 1920s or 1930s they
were born in Czechoslovakian territory to parents “not known
                               39
to be of Hungarian nationality.” Simon-2021, 579 F. Supp. 3d
at 121 (citing Pls.’ Opp’n 4). From that fact, the district court
inferred that those Survivors’ parents also lived for a sufficient
period of time in territory that later became Czechoslovakia, so
meet the requirements for citizenship under Czechoslovakian
domestic law. See Simon-2021, 579 F. Supp. 3d at 131, 133-
35. The court therefore concluded that Bar-Or, Pressburger,
Speiser, and Perel had each plausibly alleged Czechoslovakian
nationality.

     We agree with the district court’s conclusion as to those
four Survivors, though for different reasons.            Bar-Or,
Pressburger, Speiser, and Perel each allege the minimum
requirements for Czechoslovakian citizenship under the 1919
St. Germain Treaty. Article 6 of that Treaty provides that “[a]ll
persons born in Czecho-Slovak territory who are not born
nationals of another State shall ipso facto become Czecho-
Slovak nationals.” St. Germain Treaty art. 6. That provision
requires that the Survivors have been born in Czechoslovakia
after its formation, which is precisely what those four plaintiffs
allege. Bar-Or “was born in 1928 in Korosmezo (Jasina), in
Hungarian-annexed Ruthenia (formerly Austria-Hungary, then
Czechoslovakia and now Ukraine).” Simon SAC ¶ 22 (J.A.
242). Pressburger “was born in Prague in 1933.” Id. ¶ 39 (J.A.
246). Speiser “was born on October 12, 1928, in Ersekujvar,
Czechoslovakia.” Id. ¶ 41 (J.A. 247). And Perel “was born in
Ersekujvar [Czechoslovakia] . . . on February 7, 1927.” Id.
¶ 81 (J.A. 256). Those Czechoslovakian Territory Survivors
have thereby adequately alleged Czechoslovakian nationality.
We accordingly affirm the district court’s denial of the
defendants’ motion to dismiss their claims.

    As for the Lebovics sisters, we reverse. The district court
erroneously concluded that the sisters’ plausible allegation that
they were “raised in Tarackoz in Hungarian-annexed
                               40
Ruthenia,” Id. ¶ 10 (J.A. 239), supports an inference that they
were Czechoslovakian nationals at the time of the alleged
takings, see Simon-2021, 579 F. Supp. 3d at 131-32. Not so.
Being “raised” in Czechoslovakian territory is insufficient,
even under the St. Germain Treaty, to plausibly allege
Czechoslovakian nationality because we cannot reasonably
infer from that allegation that the sisters were born there; being
“raised” in a place is distinct from being “born” there, as the
district court itself noted. See id. at 132. Although the
pleadings do not specify the Lebovics sisters’ place and date of
birth, the Survivors’ counsel stated at oral argument that they
were all “born in Czechoslovakia” after its formation. Oral
Arg. 47:36-39; see id. at 47:06-36. Therefore, because it
appears the five Lebovics sisters may be able to cure the
jurisdictional defects in their complaint, we direct the district
court to dismiss their claims without prejudice.

     Finally, we reject the defendants’ argument that the
Czechoslovakian Territory Survivors were required to obtain a
permit to acquire Czechoslovakian nationality pursuant to
Article 62 of the Trianon Treaty. The Survivors assert that the
defendants forfeited this argument because they did not raise it
before the district court. We nevertheless exercise our
discretion to address this issue on appeal. The defendants’
reading of the Trianon Treaty does not withstand close
scrutiny. First, the permit requirement in Article 62 covers a
limited category of individuals that does not include the
Czechoslovakian Territory Survivors. To understand Article
62’s scope, we begin with the provision it modifies: Article 61.

     Article 61 of the 1920 Trianon Treaty assigned new
nationalities to citizens of the former Austro-Hungarian
Empire. It provides:
                               41
       Every person possessing rights of citizenship
       . . . in territory which formed part of the
       territories of the former Austro-Hungarian
       Monarchy shall obtain ipso facto to the
       exclusion of Hungarian nationality the
       nationality of the State exercising sovereignty
       over such territory.

Treaty of Trianon art. 61.          Article 61 thus grants
Czechoslovakian nationality to citizens of any territory of the
Austro-Hungarian Monarchy that was transferred to the newly
formed Czechoslovakian state. See id.

     Article 62 then limits the scope of Article 61’s
reassignment of nationalities. It states:

       Notwithstanding the provisions of Article 61,
       persons who acquired rights of citizenship after
       January 1, 1910, in territory transferred under
       the present Treaty to [Czechoslovakia], will not
       acquire [Czechoslovakian] nationality without
       a permit from the [Czechoslovakian] State . . . .

Id. art. 62. Read in context with Article 61, the phrase “persons
who acquired rights of citizenship after January 1, 1910, in
territory transferred under the present Treaty to
[Czechoslovakia],” refers to persons who acquired citizenship
in the Austro-Hungarian Empire after 1910 in the territories
that were “transferred” to Czechoslovakia in 1918; it does not
refer more broadly to all persons who acquired
Czechoslovakian citizenship after January 1, 1910. Id. Indeed,
Czechoslovakia did not exist as an independent state until 1918
so it would have been impossible for an individual to acquire
Czechoslovakian citizenship between 1910 and 1918.
                               42
     Accordingly, we read Article 62’s permit requirement to
cover those who acquired citizenship in the Austro-Hungarian
Empire in the window after January 1910 and before the
formation of Czechoslovakia in 1918—in other words, late-
arriving Austro-Hungarian citizens without deep roots in the
territory that became Czechoslovakia. See Treaty of Trianon
art. 62. Because Bar-Or, Pressburger, Speiser, and Perel each
allege that they were born after 1920, see Simon SAC ¶¶ 22,
39, 42, 81 (J.A. 242, 246-47, 256)—and because the Lebovics
sisters may amend to allege as much, see Oral Arg. 47:06-38—
they do not fall into the category of persons covered by the
permit requirement in Article 62 of the Trianon Treaty.

     Second, and in any event, even if the defendants’ reading
of Article 62 were correct, Article 65 of the Trianon Treaty
expressly preserves rights to choose any other nationality
available under earlier treaties between the Allied and
Associated Powers and Czechoslovakia. See Treaty of Trianon
art. 65. Specifically, Article 65 provides that the Treaty of
Trianon does not limit the ability of persons it covers to
“choose any other nationality which may be open to them”
pursuant to other treaties “concluded . . . between any of the
Allied and Associated Powers themselves,” including the St.
Germain Treaty. Id. Therefore, even assuming the permit
requirement in Article 62 of the Trianon Treaty applied to the
Survivors, it would not have eliminated the option to accept
Czechoslovakian nationality available to the Survivors under
Article 6 of the St. Germain Treaty.

     Before proceeding, we acknowledge that the Survivors did
not draw on the St. Germain Treaty in support of their
nationality claims before the district court. Nor did the district
court consider it. See Simon-2021, 579 F. Supp. 3d at 129-35.
Ordinarily, we refrain from “consider[ing] an issue not passed
upon below.” Liff v. Off. of the Inspector Gen. for the U.S.
                               43
Dep’t of Lab., 881 F.3d 912, 919 (D.C. Cir. 2018) (quoting
Singleton v. Wulff, 428 U.S. 106, 120 (1976)). However, we
have discretion to do so “as may be justified by the
[circumstances] of individual cases.” Id. We elect to exercise
that discretion here. Interpreting Article 6 of the St. Germain
Treaty and understanding how it operates in the context of the
Czechoslovakian Territory Survivors’ nationality claims does
not require any fact finding or “depend on any additional facts
not considered by the district court,” id. (quoting Roosevelt v.
E.I. Du Pont de Nemours & Co., 958 F.2d 416, 419 n.5 (D.C.
Cir. 1992)), as demonstrated by the preceding analysis.
Addressing the Survivors’ arguments under the St. Germain
Treaty also “avoids unnecessary expenditure of judicial
resources and expedites final resolution of the parties’
dispute.” Id.

                               3.

     That brings us to the Survivors’ cross appeal. They
contend that the district court erred in dismissing the claims of
Tzvi Zelikovitch and Ella Feuerstein Schlanger. We affirm the
district court’s dismissal of those two Survivors’ claims.
However, we conclude the district court should have dismissed
their claims without prejudice.

     As they stand, the allegations in the Second Amended
Complaint fail to push Zelikovitch and Schlanger’s nationality
claims across the line from conceivable to plausible. Recall
that Article 6 of the St. Germain Treaty provides “[a]ll persons
born in Czecho-Slovak territory who are not born nationals of
another State shall ipso facto become Czecho-Slovak
nationals.” St. Germain Treaty art. 6 (emphasis added).
Accordingly, if Zelikovitch and Schlanger were born nationals
of another state (e.g., by descent), even proof that they were
                               44
born in Czechoslovakian territory would not, per Article 6,
have made them Czechoslovakian nationals. See id.

     Although the Second Amended Complaint alleges that
Zelikovitch and Schlanger were each born in Czechoslovakian
territory, the pleadings also suggest that they may have been
born nationals of another State—namely, Hungary. See Simon
SAC ¶¶ 15, 73 (J.A. 240, 254). According to the Survivors,
and as summarized by the district court, under Hungarian law
at the time, “one acquired Hungarian citizenship . . . by descent
from a citizen parent.” Simon-2021, 579 F. Supp. 3d at 120
(quoting Pls.’ Opp’n 25-26). And the pleadings provide reason
to believe Zelikovitch and Schlanger’s parents may have been
Hungarian citizens at the time of Zelikovitch and Schlanger’s
births. As for Zelikovitch, the Second Amended Complaint
alleges that his parents were “both Hungarian citizens.” Simon
SAC ¶ 15 (J.A. 240) (emphasis added). With respect to
Schlanger, the pleadings allege she was “born in 1930 to a
Hungarian family resident in Benedike, Czechoslovakia,
approximately 10 km from Munkács.” Id. ¶ 73 (J.A. 254)
(emphasis added). In light of those allegations, we cannot
conclude that it is plausible, as opposed to merely possible, that
Zelikovitch and Schlanger acquired Czechoslovakian
nationality per Article 6 of the St. Germain Treaty upon birth.
The district court therefore correctly granted the defendants’
motion to dismiss the claims of Zelikovitch and Schlanger.

     That leaves the question whether the district court
correctly dismissed their claims with prejudice. The “standard
for dismissing a complaint with prejudice is high.” Rudder v.
Williams, 666 F.3d 790, 794 (D.C. Cir. 2012) (quoting Belizan
v. Hershon, 434 F.3d 579, 583 (D.C. Cir. 2006)). Dismissal
with prejudice is warranted when “the allegation of other facts
consistent with the challenged pleading could not possibly cure
the deficiency.” Id. (quoting Belizan, 434 F.3d at 583); accord
                               45
Abbas v. Foreign Pol’y Grp., LLC, 783 F.3d 1328, 1340 (D.C.
Cir. 2015).

     Here, it is possible that Zelikovitch and Schlanger could
allege facts consistent with the Second Amended Complaint
that would support their claims of Czechoslovakian nationality.
Schlanger’s allegation that she was born to a “Hungarian
family,” Simon SAC ¶ 73 (J.A. 254), does not necessarily mean
that her parents were Hungarian citizens at the time of her birth.
And, in their briefing, the Survivors state that the complaint
should have read “Hungarian-speaking” family. Survivors’ Br.
40 n.26 (emphasis added). If the Survivors were able to amend
the complaint to clarify, for example, that Schlanger’s parents
were not Hungarian citizens but only Hungarian speakers at the
time of her birth, the pleadings would thereby plausibly allege
that Schlanger acquired Czechoslovakian nationality at birth
under Article 6 of the St. Germain Treaty. See St. Germain
Treaty art. 6.

     Similarly, the relevant allegations and filings in the record
regarding Zelikovitch leave open the possibility that he did not
inherit Hungarian nationality from his parents, and thus would
have acquired Czechoslovakian nationality upon birth.
Although Zelikovitch’s parents may have been “Hungarian
citizens” prior to the creation of Czechoslovakia, Simon SAC
¶ 15 (J.A. 240), there is reason to believe his parents may have
become Czechoslovakian nationals upon that country’s
formation. Pursuant to Article 3 of the St. Germain Treaty,
Czechoslovakia agreed to confer Czechoslovakian nationality
on all “Hungarian nationals” who were, as of the Treaty’s
effective date, “habitually resident or possessing the rights of
citizenship . . . in territory which is or may be recognised as
forming part of Czechoslovakia.” St. Germain Treaty art. 3.
Zelikovitch’s father was born in 1895 in Uglya, an Austro-
Hungarian region that became part of Czechoslovakia upon the
                               46
country’s formation. See Zelikovitch Decl. ¶¶ 5-6 (J.A. 226);
Simon SAC ¶ 15 (J.A. 240). And, as of 1928, Zelikovitch’s
entire family was living in Uglya, where his father was a
“prosperous blacksmith.” Simon SAC ¶ 15 (J.A. 240). Those
allegations raise the possibility that Zelikovitch’s parents were
residents of Uglya at the time of Czechoslovakia’s formation
in 1918. If that is the case, Zelikovitch’s parents likely would
have acquired Czechoslovakian citizenship in 1918 unless they
affirmatively chose another citizenship. See St. Germain
Treaty arts. 3, 5. Accordingly, it remains possible that
Zelikovitch could cure the deficiency by alleging facts
consistent with the Second Amended Complaint that would
support the inference that his parents were not in fact
Hungarian nationals at the time of his birth, even if they were
Austro-Hungarian nationals before the creation of
Czechoslovakia. Dismissal without prejudice was thus
warranted as to both Zelikovitch and Schlanger.

                           *   *     *

     To sum up, four of the twelve Czechoslovakian Territory
Survivors adequately alleged they were Czechoslovakian at the
time of the takings and thus those claims survive dismissal. We
reverse the decision to allow the claims of the five Lebovics
sisters to proceed as alleged and affirm the dismissal of the
claims of Zelikovitch and Schlanger. However, we hold that
those seven plaintiffs should be permitted to amend their
pleadings if they have evidentiary support enabling them,
consistent with applicable requirements, to cure the identified
shortcomings. See Fed. R. Civ. P. 11(b)(3).

                               IV.

    As an alternative to their nationality-based arguments that
the domestic takings rule does not bar their claims, the
Survivors invoke the 1920 Treaty of Trianon as an independent
                                47
basis for demonstrating a “tak[ing] in violation of international
law” for purposes of the expropriation exception. 28 U.S.C.
§ 1605(a)(3). Their argument proceeds in two steps. First,
they contend that a “violation of the Trianon Treaty is a
violation of international law within the scope of the
expropriation exception.” Survivors’ Br. 27. Second, they
claim Hungary violated the Trianon Treaty—and specifically,
provisions guaranteeing religious free exercise and equal
protection under the law without regard to race or religion—by
“target[ing] for persecution, exploitation, and property
expropriation its Jewish inhabitants, including Survivors[,]
whether or not they were Hungarian nationals.” Id. at 29.

    The Survivors’ argument fails at step one. Recall Philipp
held that only violations of “the international law of
expropriation” count for purposes of the FSIA’s expropriation
exception. 141 S. Ct. at 715. The treaty provisions that the
Survivors claim Hungary breached—Articles 55 and 58 of the
Treaty of Trianon—do not fit that description.

     As noted, the 1920 Treaty of Trianon is the peace treaty
that formally concluded hostilities between Hungary and the
Allied and Associated Powers in World War I. See Treaty of
Trianon, preamble. The Treaty addresses a broad range of
issues related to the end of hostilities, including Hungary’s
post-war borders, id. arts. 27-35; Hungary’s recognition of the
newly      independent       states      of    Yugoslavia       and
Czechoslovakia, id. arts. 41-44, 48-52; demobilization of
Hungary’s military forces, id. arts. 102-43; and penalties and
reparations Hungary owed to the Allied and Associated
Powers, id. arts. 157-74. While some provisions of the Treaty
reference property, see, e.g., id. arts. 212, 232(1)(e), the Treaty
as a whole is not focused on property rights or state
takings. And the Survivors do not meaningfully contend that
the Treaty of Trianon as a whole is part of the “international
                                48
law of expropriation.” Philipp, 141 S. Ct. at 715. The
Survivors must therefore advance a valid argument that the
specific provisions they allege Hungary breached, Articles 55
and 58, are correctly characterized as international law of
expropriation.

     The Survivors have failed to do so. “The interpretation of
a treaty . . . begins with its text.” Medellín v. Texas, 552 U.S.
491, 506 (2008). Here, the text of the Treaty belies the
Survivors’ characterization of Articles 55 and 58 as
“international law of expropriation.” Philipp, 141 S. Ct. at 715.
Neither provision relied on by the Survivors even mentions
property or takings.          Rather, both provisions govern
“protection of minorities” in post-war Hungary. Treaty of
Trianon pt. III § IV (capitalization altered). Article 55 requires
Hungary to “assure full and complete protection of life and
liberty to all inhabitants of Hungary without distinction of
birth, nationality, language, race or religion,” and establishes
that “[a]ll inhabitants of Hungary shall be entitled to the free
exercise, whether public or private, of any creed, religion or
belief whose practices are not inconsistent with public order or
public morals.” Id. art. 55. The provision of Article 58 on
which the Survivors rely establishes similar protections for
minorities. It mandates that “Hungarian nationals who belong
to racial, religious or linguistic minorities shall enjoy the same
treatment and security in law and in fact as the other Hungarian
nationals.” Id. art. 58.

      The absence of any mention of property in Articles 55 and
58—which protect Hungarian inhabitants and nationals—is
notable given that other provisions of the Trianon Treaty
explicitly address property rights of foreign nationals. See,
e.g., id. arts. 212, 232. Article 232, for instance, situated within
the Treaty section titled “Property, Rights and Interests,”
provides “[t]he nationals of Allied and Associated Powers shall
                               49
be entitled to compensation in respect of damage or injury
inflicted upon their property, rights or interests.” Id. art.
232(e). Article 212 similarly establishes that “[t]he nationals
of the Allied and Associated Powers shall enjoy in Hungarian
territory a constant protection for their persons and for their
property, rights and interests.” Id. art. 212. These provisions
show the drafters of the Trianon Treaty specifically considered
property rights and state takings elsewhere in the Treaty, but
chose not to address property rights in Articles 55 and 58. The
text of the Treaty thus provides strong evidence that its drafters
did not intend Articles 55 and 58 to impose on Hungary
international-law obligations related to takings of its own
nationals’ property—undercutting the Survivors’ claim that
those provisions fall within the international law of
expropriation or, as the Philipp Court also called it, the
international “law of property.” 141 S. Ct. at 712.

     The Survivors counter that the provisions in Articles 55
and 58 mandating equal treatment of Hungarian nationals
regardless of race or religion necessarily encompass
protections for property rights and are therefore part of the
international law of expropriation. That argument proves too
much. The same could be said of many principles of human
rights law—i.e., that they encompass protections for property
rights. Take, for instance, the prohibition on “systematic racial
discrimination” recognized by customary international human
rights law. Third Restatement § 702(f). That principle
presumably protects against systematic property takings on the
basis of race conducted “as a matter of state policy.” Id. § 702
cmt. i. But that does not make that rule of customary human
rights law, any more than the law against genocide, a source of
international law under Philipp that could support a claim
under the FSIA’s expropriation exception. See 141 S. Ct. at
712. Philipp instructs that plaintiffs must show that the
international legal obligation on which they rely falls within
                               50
the “international law of expropriation rather than of human
rights.” Id. (emphasis added). On that score, the Survivors
come up short. Given the lack of any reference to property in
Articles 55 and 58, in contrast to other provisions of the
Trianon Treaty, we conclude that the Survivors have failed to
advance a viable argument that those Articles constitute
“international law of expropriation” for purposes of the FSIA’s
expropriation exception. Id. at 715.

     There is no question that Hungary’s persecution of its
Jewish population during the Holocaust breached its
obligations under Articles 55 and 58 of the Treaty of Trianon.
But the Survivors have failed to demonstrate that Hungary’s
alleged breach of the Trianon Treaty amounted to a “violation
of international law” within the meaning of the FSIA’s
expropriation exception. See Philipp, 141 S. Ct. at 715.

                               V.

     We turn next to the Hungarian defendants’ argument that,
even assuming the Survivors were non-Hungarian nationals at
the time of the alleged takings, their claims are barred by the
FSIA’s “treaty exception.” That exception is codified in Title
28, Section 1604, which provides that the FSIA’s baseline
grant of immunity to foreign sovereigns is “[s]ubject to
existing international agreements to which the United States
[was] a party at the time of enactment of th[e] Act.” 28 U.S.C.
§ 1604. The “exception applies when international agreements
‘expressly conflict’ with the immunity provisions of the
FSIA.” Amerada Hess, 488 U.S. at 442 (formatting modified)
(quoting H.R. Rep. No. 94-1487, at 17 (1976); S. Rep. No. 94-
1310, at 17 (1976)). Under the exception, “if there is a conflict
between the FSIA and such an agreement regarding the
availability of a judicial remedy against a contracting state, the
                               51
agreement prevails.” de Csepel II, 859 F.3d at 1100 (quoting
de Csepel I, 714 F.3d at 601).

     The Hungarian defendants’ claim to immunity under the
treaty exception rests on the 1947 Treaty of Peace, which
formally established peaceful relations between Hungary and
the Allied and Associated Powers following World War II. See
Simon I, 812 F.3d at 136. According to the defendants, the
1947 Treaty provides “the exclusive means for non-Hungarian
claimants to recover from Hungary for wartime property
losses,” thereby barring any non-Hungarian Survivors from
proceeding under the FSIA pursuant to the treaty exception.
Hungary Br. 30.

      Two provisions of the 1947 Treaty are relevant here:
Articles 26 and 27. The former requires Hungary to “restore
all legal rights and interests in Hungary of the United Nations
and their nationals as they existed on September 1, 1939,” and
to “return all property in Hungary of the United Nations and
their nationals as it now exists.” 1947 Treaty art. 26(1). Article
26 further provides that, “[i]n cases where the property has not
been returned within six months from the coming into force of
the present Treaty, application shall be made to the Hungarian
authorities not later than twelve months from the coming into
force of the Treaty,” except in certain cases. Id. art. 26(2).
Article 26 defines covered “United Nations nationals” as
“individuals who [we]re nationals of any of the United
Nations . . . at the coming into force of the present Treaty,”
which included Czechoslovakia, and all persons who, “under
the laws in force in Hungary during the war, ha[d] been treated
as enemy.” Id. art. 26(9)(a). Article 27, for its part, requires
Hungary to provide restoration of (or compensation for)
property that the Hungarian government seized during the war
from “persons under Hungarian jurisdiction” whom Hungary
                              52
subjected to such seizures “on account of the[ir] racial origin
or religion.” Id. art. 27(1).

     The defendants acknowledge we already rejected their
argument that Article 27 of the 1947 Treaty forecloses extra-
treaty means of recovery. See Hungary Br. 28-29; Simon I, 812
F.3d at 140; see also Simon-2021, 579 F. Supp. 3d at 127 n.26
(D.D.C. 2021) (declining to revisit the treaty exception). In
Simon I, we held that “Article 27 secures one means by which
Hungarian victims can seek recovery against Hungary for their
wartime property losses, but not to the exclusion of other
available remedies.” 812 F.3d at 140. We therefore concluded
the defendants had failed to identify an “express conflict
between an ‘existing international agreement[]’ and the FSIA’s
other immunity exceptions for purposes of the FSIA’s treaty
exception.” Id. (quoting 28 U.S.C. § 1604).

     The Hungarian defendants claim our Simon I ruling poses
no obstacle to their renewed treaty-exception argument. They
argue that, if the Survivors were non-Hungarian nationals at
the time of the alleged takings, then Article 26, rather than
Article 27, of the 1947 Treaty would apply to their claims. And
Article 26, the defendants argue, provides the exclusive means
by which non-Hungarians may seek compensation for property
taken from them by Hungary during World War II, thereby
barring the Survivors from proceeding under the FSIA.

     The Hungarian defendants’ argument falters at the outset.
Their threshold claim—that Article 26 alone covers the
Survivors’ property losses if they are indeed non-Hungarian
nationals—is belied by the text of the 1947 Treaty. By its plain
terms, Article 27 also applies. It establishes a restoration-or-
compensation scheme for property seized by the Hungarian
government during the war from “persons under Hungarian
jurisdiction” who were targeted on account of their race or
                                53
religion. 1947 Treaty art. 27(1). It nowhere limits its coverage
to Hungarian nationals under Hungarian jurisdiction. See id.
Other provisions of the Treaty confirm that its drafters
distinguished between “persons under Hungarian jurisdiction”
and “Hungarian nationals.” Article 2, for instance, provides
different protections in its first and second clauses for “persons
under Hungarian jurisdiction” as compared to “persons of
Hungarian nationality.” Id. art. 2(1)-(2); see also, e.g., id. arts.
26(4), 29(1), 29(3)-(5), 30(1)-(2), 30(4), 32(1), 32(3) (using the
phrase “Hungarian nationals”). Because there is no dispute
that the Survivors were in territory annexed by Hungary and
thereby “under Hungarian jurisdiction,” nor is there any
dispute the Survivors adequately allege that Hungary seized the
Survivors’ property on account of their religion, Article 27
applies to their claims irrespective of their status as non-
Hungarian nationals. Id. art. 27(1).

     That raises the question, however, whether Article 27 as
applied to non-Hungarian nationals provides the exclusive
means for such persons to obtain recovery for Hungary’s
seizure of their property during the war. As noted, our ruling
in Simon I assumed that the plaintiffs were Hungarian nationals
for purposes of the treaty-exception inquiry. See 812 F.3d at
136-40. We conclude, however, that our reading of the
Treaty’s text in Simon I holds as applied to claims brought by
non-Hungarian nationals.

     As we explained in Simon I, “[t]he terms of Article 27 do
not speak in the language of exclusivity.” Id. at 137. Although
Article 27 provides certain rights to victims of the Holocaust
regarding property the Hungarian government confiscated, “it
says nothing about whether those rights are exclusive of other
claims” that covered individuals might bring. Id. Other World
War II peace treaties, by contrast, contain express waivers of
extra-treaty claims. See id. at 137-38 (citing Treaty of Peace
                               54
with Japan art. 14(a)-(b), Sept. 8, 1951, 3 U.S.T. 3169). And,
as we explained, “[t]he absence of any such waiver language
in Article 27 is all the more notable given that the 1947 Treaty
itself contains an express waiver of certain other claims.” Id.
at 138. Indeed, Article 32 of the 1947 Treaty states that
“Hungary waives all claims of any description against the
Allied and Associated Powers on behalf of the Hungarian
Government or Hungarian nationals arising directly out of the
war,” 1947 Treaty art. 32(1), but includes no reciprocal waiver
of all claims by Allied and Associated Powers or their nationals
against Hungary, see id. arts. 27, 32. The text of the Treaty
thus makes clear that Article 27 does not foreclose extra-treaty
claims for covered individuals, including non-Hungarian
nationals—and thus does not immunize Hungary from the
Survivors’ suit under the FSIA’s treaty exception. See Simon
I, 812 F.3d at 140; 28 U.S.C. § 1604.

     The same goes for Article 26 of the 1947 Treaty. Like
Article 27, Article 26 speaks only to Hungary’s obligations to
compensate United Nations nationals, as defined by the Treaty.
1947 Treaty art. 26(1), (9). It does not address, let alone
foreclose, extra-treaty claims that such nationals might seek to
bring against Hungary. See id. art. 26(1). Moreover, Article
32’s one-way waiver provision—eliminating claims arising out
of the war by Hungary on behalf of itself or its nationals against
the Allied and Associated Powers but not vice versa, id. art.
32(1)—convinces us that Article 26 lacks such exclusionary
language by design. As further evidence of its non-exclusive
nature, Article 26 overlaps in coverage with Article 27: A
United Nations national who was “under Hungarian
jurisdiction” during the war and whose property Hungary
confiscated on account of their religion would fall within the
scope of both Articles. Id. art. 27; see id. arts. 26-27. We
therefore do not read Article 26 to provide an exclusive avenue
for covered individuals to seek compensation for property
                              55
losses during the war. And, accordingly, we see no “express
conflict” between permitting the Survivors’ action to proceed
under the FSIA and Article 26 of the 1947 Treaty. Simon I,
812 F.3d at 140; accord Amerada Hess, 488 U.S. at 441-43.

     The Hungarian defendants counter that, because our
reasoning in Simon I “relied on Plaintiffs’ Hungarian
nationality to hold that the treaty exception did not bar” their
claims, we must reach a “different result” now that the
Survivors deny their Hungarian nationality. Hungary Br. 28-
29. But our principal reasoning in Simon I was that the Treaty’s
text did not support the defendant’s exclusive-remedy
argument. Building from there, the analysis specific to
Hungarian nationals provided “context” that we concluded
“further weigh[ed] against construing [Article 27] to foreclose
extra-treaty claims.” Simon I, 812 F.3d at 138. We found it
informative, for instance, that the Allied powers “could, and
did, impose an obligation on Hungary to provide a minimum
means of recovery to Hungarian victims for Hungary’s
wartime wrongs,” but we did not read Article 27 to implicitly
“render that means of recovery an exclusive one because [the
Allies] had no power to settle or waive the extra-treaty claims
of another country’s (Hungary’s) nationals.” Id. In other
words, the case for non-exclusivity was even stronger when
considering Article 27 as applied to Hungarian nationals. See
id. at 138-39. But, given the clear textual support detailed
above, those additional points are not necessary to our
conclusion here that neither Article 26 nor 27 bars extra-treaty
claims by non-Hungarian nationals.

     In short, we perceive no conflict between the provisions of
the 1947 Treaty relied on by the defendants and permitting
those Survivors who have plausibly alleged Czechoslovakian
nationality to proceed under the FSIA’s expropriation
exception. We thus affirm the district court’s denial of the
                               56
Hungarian defendants’ motion to dismiss the Survivors’ claims
on that ground.

                               VI.

     That brings us to the Hungarian defendants’ final
argument: that the expropriation exception’s requirement of a
nexus between the disputed property and a defendant’s
commercial activity in the United States remains unmet. The
expropriation exception requires that the property at issue in
the suit “or any property exchanged for such property” be
either (1) “present in the United States in connection with a
commercial activity carried on in the United States by the
foreign state” or (2) “owned or operated by an agency or
instrumentality of the foreign state and that agency or
instrumentality is engaged in a commercial activity in the
United States.” 28 U.S.C. § 1605(a)(3). Even as the FSIA
defines “foreign state” to include subdivisions and agencies or
instrumentalities of the state, id. § 1603, the Act describes
distinct routes to pierce the state’s immunity by reference to its
own conduct and that of its agencies or instrumentalities, id.
§ 1605. The first clause of the commercial-activity nexus
requirement addresses immunity of foreign states in terms of
the states’ own conduct, while the second clause addresses it in
terms of actions of foreign-state agencies or instrumentalities.
Id. § 1605(a)(3); see de Csepel II, 859 F.3d at 1107. Generally
speaking, each clause specifies a requisite connection between
the defendant and both (i) “the expropriated property or
proceeds thereof” and (ii) “some kind of commercial activity
in the United States.” Simon I, 812 F.3d at 146. For ease of
reference, we use “property element” and “commercial-
activity element,” respectively, to refer to these two
components of the commercial-activity nexus requirement.
                                  57
     The district court held that the Simon plaintiffs’ suit meets
the relevant property and commercial-activity requirements as
to Hungary and MÁV. See Simon-2020, 443 F. Supp. 3d at
116. It concluded that the Simon plaintiffs adequately alleged
that both Hungary and MÁV continue to possess property
obtained in exchange for the plaintiffs’ expropriated property,
and that both engage in the requisite commercial activities in
the United States. Id. 1

      The Hungarian defendants ask us to reverse that decision.
We instead remand to the district court for factfinding as to two
points relevant to the commercial-activity nexus requirement:
first, whether the property at issue in the claims against both
Hungary and MÁV derived from the Simon plaintiffs’
expropriated property and, second, whether MÁV engages in
commercial activity in the United States. As to those
components of the commercial-activity requirement, the
district court, proceeding in the wake of jurisdictional
discovery, did not sufficiently respond to the Hungarian
defendants’ factual challenges to the court’s jurisdiction. First,
on the property element, the district court failed to “go beyond
the pleadings and resolve [the] disputed issues of fact.”
Phoenix Consulting, Inc. v. Republic of Angola, 216 F.3d 36,
40 (D.C. Cir. 2000). Second, on MÁV’s commercial activity
in the United States, the district court erroneously relied on the
pleading-stage ruling on the point in Simon I as law of the case,
so did not make the findings of fact called for in response to
the defendants’ factual challenge. Finally, as for Hungary’s

1
      In Heller, the district court did not reach this issue because it
concluded that the “the domestic takings rule alone suffice[d] to
grant the [Hungarian defendants’] motion [to dismiss].” Heller,
2022 WL 2802351, at *9. Given that we affirm the district court’s
dismissal of the Heller plaintiffs’ claims on domestic takings rule
grounds, we do not address whether the Heller plaintiffs’ claims
satisfy the commercial-activity nexus requirement.
                                58
commercial activity, we affirm the district court’s
conclusion—based on stipulated facts—that Hungary engaged
in the requisite commercial activity through its issuance of
bonds in the United States. We address each of these three
components in turn.

                                 A.

     The district court did not make findings of fact regarding
the disputed property and the defendants’ commercial activity
in the United States, as required in response to the Hungarian
defendants’ factual challenges to the applicability of the
FSIA’s expropriation exception. The district court’s task in
assessing jurisdiction under the FSIA varies depending on
whether the defendant presents a legal or a factual challenge.
See Phoenix Consulting, 216 F.3d at 40. “If the defendant
challenges only the legal sufficiency of the plaintiff’s
jurisdictional allegations, then the district court should take the
plaintiff’s factual allegations as true and determine whether
they bring the case within any of the exceptions to immunity
invoked by the plaintiff,” id., drawing “all reasonable
inferences in [the plaintiff’s] favor,” Schubarth, 891 F.3d at
401. The Rule 12(b)(1) standard in this context “is similar to
that of Rule 12(b)(6), under which dismissal is warranted if no
plausible inferences can be drawn from the facts alleged that,
if proven, would provide grounds for relief.” Valambhia, 964
F.3d at 1139 (quoting Schubarth, 891 F.3d at 398).

     By contrast, when a defendant moves beyond assuming
the truth of well-pleaded facts and seeks at the jurisdictional
threshold to challenge the factual basis of the court’s
jurisdiction—for instance, by factually disputing the Simon
plaintiffs’ jurisdictional allegations—“the court must go
beyond the pleadings and resolve any disputed issues of fact
the resolution of which is necessary” to resolve the Rule
                               59
12(b)(1) motion. Phoenix Consulting, 216 F.3d at 40. Put
simply, if a decision about the existence of jurisdiction under
the FSIA “requires resolution of factual disputes, the court will
have to resolve those disputes.” Helmerich, 581 U.S. at 187.
In so doing, “[t]he district court retains ‘considerable latitude
in devising the procedures it will follow to ferret out the facts
pertinent to jurisdiction,’ but it must give the plaintiff ‘ample
opportunity to secure and present evidence relevant to the
existence of jurisdiction.’” Phoenix Consulting, 216 F.3d at 40
(quoting Prakash v. Am. Univ., 727 F.2d 1174, 1179-80 (D.C.
Cir. 1984)).

     “Regardless of the procedures the court follows, however,
the sovereign ‘defendant bears the burden of proving that the
plaintiff’s allegations do not bring its case within a statutory
exception to immunity.’” Price, 389 F.3d at 197 (quoting
Phoenix Consulting, 216 F.3d at 40); accord de Csepel v.
Republic of Hungary, 27 F.4th 736, 743 (D.C. Cir. 2022). That
is because sovereign immunity is an “affirmative defense.”
EIG Energy, 894 F.3d at 345. Accordingly, the “burden of
proof in establishing the inapplicability of [the FSIA’s]
exceptions is upon the party claiming immunity.” Transam.
S.S. Corp. v. Somali Democratic Republic, 767 F.2d 998, 1002
(D.C. Cir. 1985) (citing H.R. Rep. No. 94-1487, at 6-7 (1976),
reprinted in 1976 U.S.C.C.A.N. 6604); see H.R. Rep. No. 94-
1487, at 17 (1976), reprinted in 1976 U.S.C.C.A.N. at 6616.

     Here, the Hungarian defendants raised a factual challenge
to the Survivors’ allegations regarding the property element.
Although their motion-to-dismiss briefing principally argued
that the Simon plaintiffs’ pleadings had failed to satisfy the
“heightened pleading standard” that they claimed Helmerich
established, Hungary Mot. to Dismiss 22; see id. at 22-24; see
also Part III.B, supra, they also filed fact declarations as
attachments to their motion to dismiss, see Hungary Mot. to
                               60
Dismiss, Exs. 1-6; Dkt. Sheet 29 (J.A. 29). The Hungarian
defendants relied on those declarations to factually question the
Simon plaintiffs’ allegations that property exchanged for their
confiscated property is present in the United States in
connection with Hungary’s commercial activity or possessed
by MÁV. See Hungary Mot. to Dismiss 23; Dkt. Sheet 29 (J.A.
29). Those declarations drew on Hungarian state archival
records related to the Holocaust to conclude that it is
impossible to trace the current location of the property Hungary
allegedly seized or the proceeds thereof. See Botos Decl. ¶ 4
(J.A. 823); Csösz Decl. ¶ 5 (J.A. 834); Kovács Decl. ¶ 4 (J.A.
842).

     The Simon Survivors countered by citing evidence in the
record that “Hungary nationalized the expropriated property,
sold it, and mixed the proceeds with the general state funds,
which are used to fund various governmental commercial
operations.” Survivors’ Br. 62 n.33; see id. at 62-63. They
identified three sources of record support for those facts. First,
they cited a declaration of a Hungarian attorney that describes,
and attaches as an accompanying exhibit, a 1993 decision of
the Hungarian Constitutional Court that includes the court’s
findings regarding Hungary’s expropriation and use of
property confiscated from Jews during the Holocaust. See id.
at 62-63; Second Hanák Decl. ¶ 44 (J.A. 359); Second Hanák
Decl., Ex. 8 (J.A. 414-40). The Simon plaintiffs’ second
declaration attaches and describes microfilm archives at the
Holocaust Museum in Washington, D.C., that show “records
of the confiscation, processing, and distribution of Jewish
property in Hungary 1944.” Fax Decl. ¶¶ 7-8 (J.A. 452); Fax
Decl., Ex. 15 (see J.A. 750-61); Fax Decl., Ex. 16 (J.A. 762-
71). Third, they submitted a study co-authored by one of the
Hungarian defendants’ declarants, Dr. László Csösz, which,
inter alia, identifies a Hungarian “Ministry of Finance’s
account” where proceeds from the liquidation of Jewish assets
                               61
were deposited. Fax Decl., Ex. 17, at 23 (J.A. 794); see id. at
1-2 (J.A. 772-73). The Simon Survivors also submitted
evidence of the presence of Hungarian funds used in
connection with Hungary’s commercial activity in the United
States, as further discussed below.

     In this posture, resolving the Hungarian defendants’
motion to dismiss required resolving the “dispute over the
factual basis of the court’s subject matter jurisdiction under the
FSIA.” Phoenix Consulting, 216 F.3d at 40. The district court
was, accordingly, required to “go beyond the pleadings” and
make findings of fact germane to the expropriation exception’s
property element—namely, whether property defendants
received in exchange for the Simon plaintiffs’ confiscated
property is present in the United States in connection with
Hungary’s commercial activity there or is possessed by MÁV.
Id.; see also Helmerich, 581 U.S. at 187.

     The district court did not do so here: It examined a mix of
factual allegations and evidence submitted by the parties but
does not appear to have undertaken the requisite factfinding to
support its jurisdiction. See Simon-2020, 443 F. Supp. 3d at
103-05. The district court continued to view the central
question as whether the Simon plaintiffs’ “allegations suffice
to raise a plausible inference that the defendants retain some
portion of the expropriated property.” Id. at 104 (emphasis
added). It characterized the evidence submitted by the Simon
plaintiffs as “bolster[ing] the plausibility of [those]
allegations,” and framed its conclusion as one that the
“allegations suffice” to establish jurisdiction under the FSIA.
Id. at 104, 116. Rather than find that the defendants had (or
had not) established by a preponderance of the evidence that
their property does not derive from the challenged
expropriations, see Simon I, 812 F.3d at 147, the district court
referred to the Simon plaintiffs’ allegations rather than
                              62
evidence, concluding that the defendants’ “declarations do not
affirmatively disprove the plausible inference drawn from the
plaintiffs’ complaint,” Simon-2020, 443 F. Supp. 3d at 105.
Remand is therefore warranted to enable the district court to
make the necessary factual findings. See, e.g., Phoenix
Consulting, 216 F.3d at 38, 41-40; see also Helmerich, 581
U.S. at 187.

     The Hungarian defendants advance two primary
counterarguments in support of their request for reversal,
neither of which carries the day. They first argue that the
district court erred by applying a legal standard that Helmerich
displaced. See Hungary Br. 37. As discussed in Part III.B,
supra, the defendants misread Helmerich. Next, the Hungarian
defendants contend that, in any event, they are entitled to
reversal because the Simon plaintiffs failed to “produce
evidence tracing property in the United States or possessed by
MÁV to property expropriated from them during World War
II.” Id. at 44. That argument fails at the gate: The plaintiffs
had no such burden here.

     The FSIA’s expropriation exception requires that the
property at issue, “or any property exchanged for such
property,” be present in the United States in connection with
the foreign state’s commercial activity, or “owned or operated
by an agency or instrumentality of the foreign state” that
engages in commercial activity in the United States. 28 U.S.C.
§ 1605(a)(3) (emphasis added). Congress knew that an
expropriating foreign state or instrumentality thereof might
“exchange[]” or liquidate the stolen property—i.e. convert it to
cash or cash equivalents. Id. It included language in the FSIA
to enable plaintiffs to satisfy the expropriation exception’s
jurisdictional nexus requirements in those circumstances. Id.
                                63
     Requiring plaintiffs whose property was liquidated to
allege and prove that they have traced funds in the foreign
state’s or instrumentality’s possession to proceeds of the sale
of their property would render the FSIA’s expropriation
exception a nullity for virtually all claims involving
liquidation. Given the fungibility of money, once a foreign
sovereign sells stolen property and mixes the proceeds with
other funds in its possession, those proceeds ordinarily become
untraceable to any specific future property or transaction. The
Hungarian defendants’ proposed rule could thus thwart most
claims under the expropriation exception: A foreign sovereign
would need only commingle the proceeds from illegally taken
property with general accounts to insulate itself from suit under
the expropriation exception. We decline to ascribe to Congress
an intent to create a safe harbor for foreign sovereigns who
choose to commingle rather than segregate or separately
account for the proceeds from unlawful takings.

     We came to a similar conclusion in Kilburn v. Socialist
People’s Libyan Arab Jamahiriya, 376 F.3d 1123 (D.C. Cir.
2004), with respect to tracing foreign-state funds for purposes
of material support under the FSIA’s terrorism exception. See
id. at 1130-33; 28 U.S.C. § 1605(a)(7) (2002). 2 That exception
requires a link between a foreign state’s material support and
the act of terrorism that harmed the plaintiff. 28 U.S.C.
§ 1605(a)(7) (2002); see Kilburn, 376 F.3d at 1130. The
defendants argued that, for the exception to apply, the plaintiff

2
      In 2008, after our decision in Kilburn, Congress relocated the
terrorism exception from 28 U.S.C. § 1605(a)(7) to 28 U.S.C.
§ 1605A, “but the relevant language remains substantially identical
to that considered in Kilburn.” EIG Energy, 894 F.3d at 346 n.4
(citing National Defense Authorization Act for Fiscal Year 2008,
Pub. L. 110-181 § 1083(a), (b)(1)(A)(iii), 122 Stat. 3, 338-41). In
the interest of consistency with Kilburn’s references, we quote and
cite the version included in the 2002 edition of the U.S. Code.
                               64
must allege and ultimately prove that a state’s “material
support” is “directly traceable to the particular terrorist act”
that gives rise to the underlying claim. See Kilburn, 376 F.3d
at 1130 (emphasis omitted). We rejected that argument.
Because money is “fungible, and terrorist organizations can
hardly be counted on to keep careful bookkeeping records,” we
explained, “[i]mposing a jurisdictional requirement that a state
sponsor’s financial assistance to a terrorist organization must
be directly traceable to a particular terrorist act, would likely
render § 1605(a)(7)’s material support provision ineffectual.”
Id. With regard to “property taken in violation of international
law,” 28 U.S.C. § 1605(a)(3), relying on foreign sovereigns
and their agencies to segregate resulting proceeds and “keep
careful bookkeeping records” poses similar hazards, Kilburn,
376 F.3d at 1130.

     We hold that the Simon plaintiffs need not produce
evidence directly tracing the liquidated proceeds of their stolen
property to funds retained by the defendants in order to survive
the defendants’ factual challenge to the court’s jurisdiction
under the FSIA’s expropriation exception. Rather, because
“the sovereign ‘defendant bears the burden of proving that the
plaintiff’s allegations do not bring its case within a statutory
exception to immunity,’” Price, 389 F.3d at 197 (quoting
Phoenix Consulting, 216 F.3d at 40); accord EIG Energy, 894
F.3d at 344-45, defendants who wish to disclaim property they
seized and liquidated must at least affirmatively establish by a
preponderance of the evidence that their current resources do
not trace back to the property originally expropriated. In
keeping with the parties’ respective burdens, evidence that
“merely confirm[s] the difficulty of tracing individual paths of
exchange,” will—as the district court observed—“hurt[] rather
than help[] the defendants” in that endeavor. Simon-2020, 443
F. Supp. 3d at 105.
                               65
     It is the province of the district court to find facts,
including the requisite jurisdictional facts regarding the
property element. The district court has wide “latitude [to]
devis[e] the procedures” necessary “to ferret out the facts
pertinent to jurisdiction,” Phoenix Consulting, 216 F.3d at 40
(quoting Prakash, 727 F.2d at 1179), should it determine that
any additional jurisdictional discovery or evidentiary
submissions would be appropriate. We therefore remand to the
district court to make the factual findings necessary to a
determination whether the property component of the
commercial-activity nexus requirement is satisfied as to
Hungary and MÁV.

                               B.

     Next, we turn to the question whether MÁV engages in
commercial activity in the United States. Here, too, we
conclude the district court failed appropriately to respond to the
Hungarian defendants’ factual challenge by making findings of
fact. Instead, the district court relied on law-of-the-case
doctrine to treat Simon I’s pleading-stage ruling on the point as
dispositive. See Simon-2020, 443 F. Supp. 3d at 111-12, 116.

     Law-of-the-case doctrine applies only where a prior ruling
in the case resolved the same question that a party asks the
court to revisit. See Wye Oak Tech., Inc. v. Republic of Iraq,
24 F.4th 686, 698 (D.C. Cir. 2022); Kimberlin v. Quinlan, 199
F.3d 496, 500 (D.C. Cir. 1999). When the prior ruling occurred
at a “distinct procedural” stage of the case, it may not provide
the type of resolution required at a later stage. Wye Oak, 24
F.4th at 698. We deemed law-of-the-case doctrine inapplicable
in Wye Oak, for instance, because the prior ruling at issue
assessed only “the legal sufficiency of [the] complaint for the
purpose of proceeding to discovery,” and we were then
reviewing a post-trial judgment made on the basis of “a
                              66
developed factual record” following a “full adversarial
hearing.” Id. at 697-98.

     Given those principles, the district court erred by deeming
dispositive Simon I’s ruling on MÁV’s commercial activity. In
Simon I, we determined that the plaintiffs had adequately
pleaded MÁV’s commercial activity. See 812 F.3d at 147-48.
We accordingly reversed the district court’s grant of the
Hungarian defendants’ motion to dismiss. In so doing, we
noted that questions of proof would await “any factual
challenge by the Hungarian defendants.” Id. at 147, 151.

     The Hungarian defendants then raised a factual challenge
with respect to MÁV’s commercial activity. See Hungary Mot.
to Dismiss 9-11; Dkt. Sheet 29 (J.A. 29); Simon-2020, 443 F.
Supp. 3d at 112-14. They factually contested the Simon
plaintiffs’ allegations that MÁV-START, another Hungarian
entity, is an agent of MÁV, and argued that MÁV cannot be
subjected to the jurisdiction of a U.S. court based on the
activities of MÁV-START. Hungary Mot. to Dismiss 9-11.
The district court granted the parties’ request for limited
jurisdictional discovery “concerning the averments in the
declarations [filed] in support of” the Hungarian defendants’
motion to dismiss. Dkt. Sheet 29 (J.A. 29) (internal quotation
marks omitted). And the Simon plaintiffs thereafter filed a
declaration and accompanying exhibits regarding MÁV’s
relationship with MÁV-START in support of their opposition
to the defendants’ motion to dismiss. See Dkt. Sheet 31 (J.A.
31); Schopler Decl. ¶¶ 3-18 (J.A. 1632-34); Schopler Decl.,
Exs. 11-17 (J.A. 1678-99). This factual challenge regarding
the existence of a principal-agent relationship between MÁV
and MÁV-START obligated the district court to go beyond the
pleadings to resolve that dispute. See Phoenix Consulting, 216
F.3d at 40.
                               67
     In taking up the factual challenge, however, the district
court began its analysis by stating that it was “bound by the law
of the case,” and by what it described as the Simon I court’s
“finding about MÁV’s commercial nexus to the United
States.” Simon-2020, 443 F. Supp. 3d at 111; see also id. at
111-12 (reasoning that the defendants’ factual challenge to
MÁV’s commercial-activity nexus would succeed “only if one
of the limited exceptions to the law of the case doctrine is
met”). Even as the court went on to discuss the factual record
developed by the parties following Simon I, it expressly
invoked law of the case and grounded its conclusion regarding
MÁV’s commercial activity in what it described as this court’s
“prior finding” of MÁV’s commercial activity in the United
States. See id. at 116.

     We do not suggest that the district court was wrong to
draw on the legal ruling in Simon I, but only that doing so was
insufficient once defendants pressed their factual challenge.
We are in no position to discern whether the district court
would have reached the conclusion about MÁV’s commercial
activity that it announced had it expressly made factual
findings on the point. Accordingly, we remand for the district
court to determine as a factual matter based on the evidence
whether MÁV engages in commercial activity in the United
States.

                               C.

     That leaves the Hungarian defendants’ challenge
regarding Hungary’s commercial activity in the United States.
We note, at the outset, that the procedural history on this issue
differs from that of the previous two points in one respect:
Whereas we deemed other allegations sufficient in Simon I, we
held that the First Amended Complaint’s “allegations about
Hungary’s commercial activity fail[ed] to demonstrate
                               68
satisfaction of § 1605(a)(3)’s nexus requirement.” 812 F.3d at
148. As we explained, “the plaintiffs put forward only the bare,
conclusory assertion that ‘property is present in the United
States in connection with commercial activity carried on by
Hungary within the United States.’ There is nothing more.”
Id. (quoting Simon First Am. Compl. ¶ 83 (J.A. 119)). We
“express[ed] no view,” however, “on whether [the plaintiffs
could] (or should be allowed to) amend the complaint in this
regard.” Id.

     On remand, the district court permitted the Simon
plaintiffs to amend. See Dkt. Sheet 25 (J.A. 25). The Simon
plaintiffs did so, see id. at 26 (J.A. 26), and added, inter alia,
allegations regarding Hungary’s issuance of bonds and military
purchases in the United States, see Simon SAC ¶¶ 98-101 (J.A.
260-62). The Hungarian defendants then renewed their motion
to dismiss, again arguing, inter alia, that the Simon plaintiffs
had failed as a legal matter to satisfy the commercial-activity
element as to Hungary. See Dkt. Sheet 29 (J.A. 29); Simon-
2020, 443 F. Supp. 3d at 106-11. Following jurisdictional
discovery, see Dkt. Sheet 29 (J.A. 29), the parties submitted a
Joint Stipulation of Facts relevant to Hungary’s commercial
activity in the United States, see Joint Stip. (J.A. 1155-70).
Relying principally on the facts set forth in the Joint
Stipulation, the district court concluded Hungary engaged in
the commercial activity required for purposes of the
expropriation exception. See Simon-2020, 443 F. Supp. 3d at
106-11. In particular, the court held that “Hungary’s bond
offerings and military equipment purchases are sufficient to
meet the commercial activity prong.” Id. at 107.

     On appeal, the Hungarian defendants argue that the district
court erred in its analysis of both the bond offerings and
military equipment purchases. They argue that the district
court erroneously accepted Hungary’s issuance of bonds and
                               69
military equipment purchases as satisfying the commercial-
activity component of the expropriation exception. In their
view, the district court misstated the central question under the
commercial-activity inquiry in analyzing Hungary’s issuance
of bonds and erred in concluding that a state’s participation in
the U.S. Foreign Military Sales Program could qualify as
commercial activity under the FSIA.

     We affirm the district court’s conclusion that the
commercial-activity prong is met based on Hungary’s issuance
of bonds. Because that is sufficient to resolve the appeal with
respect to Hungary’s commercial activity, we do not consider
Hungary’s military equipment purchases. The commercial-
activity nexus requirement, as it relates to foreign states,
requires that the expropriated “property or any property
exchanged for such property is present in the United States in
connection with a commercial activity carried on in the United
States by the foreign state.” 28 U.S.C. § 1605(a)(3). The FSIA
defines commercial activity as “either a regular course of
commercial conduct or a particular commercial transaction or
act.” Id. § 1603(d). The Act further specifies that the purpose
of an activity does not determine its commercial character.
Rather, courts should look to “the nature of the course of
conduct or particular transaction or act.” Id.

     In Republic of Argentina v. Weltover, Inc., 504 U.S. 607
(1992), the Court interpreted the term “commercial” in the
FSIA’s commercial activity exception. See id. at 612-14. It
held that a foreign state’s actions are “commercial” under the
FSIA when the state “acts, not as regulator of a market, but in
the manner of a private player within it.” Id. at 614. Applying
that standard, the Court held that Argentina’s issuance of
government bonds was a “commercial activity” under the
FSIA. Id. at 617. As the Court explained, the bonds at issue
were “in almost all respects garden-variety debt instruments”;
                               70
private parties could hold them, trade them on the international
market, and use them to secure a future stream of income. Id.
at 615. Because “private parties regularly issue [such] bonds,”
Argentina’s issuance constituted commercial activity for
purposes of the FSIA. Id. at 616.

     Application of Weltover to the relevant facts as stipulated
by the parties establishes that Hungary’s issuance of bonds in
this case qualifies as “commercial activity” within the meaning
of the FSIA. Two Hungarian bond issuances are illustrative.
See Simon-2020, 443 F. Supp. 3d at 107-08. First, in 2005,
Hungary filed a prospectus supplement with the United States
Securities and Exchange Commission (SEC) offering $1.5
billion in notes for sale globally, of which approximately $582
million was “directly sold in the United States,” with an
additional $92 million “estimated to flow back into the United
States from sales outside the United States.” Joint Stip. ¶ 21
(J.A. 1158). “The notes issued under the 2005 Prospectus
constituted direct, unconditional, unsecured and general
obligations of Hungary,” id. ¶ 25 (J.A. 1159), and the “[d]ebt
securities issued under the 2005 Prospectus were outstanding
in the United States throughout 2009, 2010, and 2011,” id. ¶ 27
(J.A. 1159)—i.e., both before and after the Simon plaintiffs
filed their complaint. Second, in 2010, Hungary filed another
prospectus supplement with the SEC. Id. ¶¶ 47-48, 51 (J.A.
1161-62). “The debt securities issued under the 2010
Prospectus” were notes due in January 2020, “bearing interest
at the rate of 6.250% per year,” accruing from January 2010,
and “payable on July 29 and January 29 of each year, beginning
on July 29, 2010.” Id. ¶ 52 (J.A. 1162). In short, these two sets
of bonds are materially indistinguishable from those at issue in
Weltover: “They may be held by private parties; they are
negotiable and may be traded on the international market . . . ;
and they promise a future stream of cash income.” 504 U.S. at
                               71
615.  Hungary’s issuance of these bonds constitutes
commercial activity within the meaning of the FSIA.

     The Hungarian defendants dispute none of this. See
Hungary Br. 52-53. Instead, they contend that Hungary’s
issuance of the bonds, although commercial in nature, is not
germane to the commercial-activity nexus required here. See
id. The real issue, they argue, is “who engaged in ‘commercial
activity in the United States’ in connection with property
exchanged for expropriated property.” Id. at 53 (quoting 28
U.S.C. § 1605(a)(3)). According to the Hungarian defendants,
“[t]he bonds themselves are not property exchanged for
property expropriated from [p]laintiffs.” Id. Rather, “[t]he
only conceivably relevant property in the United States would
be interest paid on the bonds to U.S. holders, and the relevant
commercial activity in the United States would be the payment
of that interest.” Id. Because a separate entity, ÁKK Zrt.
(ÁKK), made those interest payments, defendants argue, it is
ÁKK that was engaged in the relevant commercial activity, if
any. See id.; see also Joint Stip. ¶¶ 28, 55, 73-77 (J.A. 1159,
1162, 1165-66).

     That argument misunderstands the link required between
the relevant property and the foreign state’s commercial
activity in the United States. As noted, the expropriation
exception requires that the confiscated “property or any
property exchanged for such property [must be] present in the
United States in connection with a commercial activity carried
on in the United States by the foreign state.” 28 U.S.C.
§ 1605(a)(3). If money derived from the proceeds of
liquidating the Simon plaintiffs’ stolen property is present in
the United States as a result of Hungary’s commercial activity
in the United States (here, its issuance of bonds), the fact that
another entity acting for Hungary is using those funds to make
the interest payments for the bonds does not negate the fact that
                               72
the funds are “present in the United States in connection with
a commercial activity carried on in the United States by”
Hungary. Id.

     Moreover, to the extent the Hungarian defendants suggest
that Hungary’s issuance of bonds occurred “outside the United
States,” Hungary Br. 52, any such argument is foreclosed by
the record. The parties’ Joint Stipulation of Facts explicitly
states, “Hungary issued debt securities in the United States
under the 2010 Prospectus.” Joint Stip. ¶ 51 (J.A. 1162).
Additionally, as the district court explained in detail, SEC
filings produced by the Simon plaintiffs and uncontested by the
Hungarian defendants identify Hungary as the issuer of (and
entity responsible for) the debt securities offered in the United
States. See Simon-2020, 443 F. Supp. 3d at 108; see also, e.g.,
Fax Decl., Ex. 7, at 54 (J.A. 618) (SEC filing listing the
“Republic of Hungary” as the “Issuer” of the 2010 bonds, and
noting the securities being offered “constitute direct,
unconditional, general and unsecured obligations of the
Republic”); id. at 5 (J.A. 569) (SEC filing describing the 2010
bonds as “debt securities of the Republic, which are being
offered globally for sale in the United States and elsewhere
where such offer and sale is permitted”).

     The Hungarian defendants’ challenge to the district court’s
ruling on Hungary’s commercial activity is thus unavailing.
We affirm the district court’s ruling that the commercial-
activity element is satisfied as to Hungary.

                              VII.

     For the foregoing reasons, we affirm the district court’s
dismissal of the Trianon Survivors’ claims in its 2021 decision
in Simon and 2022 decision in Heller. We likewise affirm the
district court’s 2021 disposition of the Hungarian defendants’
motion to dismiss the remaining plaintiffs’ claims, with the
                                73
exception of the Lebovics sisters, Zelikovitch, and Schlanger,
whose claims we direct the district court to dismiss without
prejudice. As for the district court’s 2020 Simon decision on
the commercial-activity nexus requirement, we affirm the
district court’s ruling as to Hungary’s commercial activity.
However, we vacate the court’s ruling on the property
component of the nexus in relation to both Hungary and MÁV,
as well as on MÁV’s commercial activity. We remand for the
district court to make factual determinations on those points, as
necessary to resolve the Hungarian defendants’ challenge to
the remaining plaintiffs’ invocation of the expropriation
exception.

     We pause, at this juncture, to acknowledge the immense
gravity of the claims at issue in this case and others like it. The
atrocities committed by the Hungarian government during the
Holocaust are unspeakable. And there is no denying that the
survivors of Hungary’s genocidal campaign deserve justice.
The role of the courts of the United States in these cases
depends on the factual record before it. Our legal authority is
granted and limited by Congress. We are also checked by the
reality that even the best remedies a court can provide for past
harms are, by their nature, profoundly inadequate. That reality,
always there in the background, is starkly evident in cases like
these.

                                                      So ordered.
    RANDOLPH, Senior Circuit Judge, concurring in part and
dissenting in part: A basic judicial principle is that like cases
must be treated alike. LaShawn A. v. Barry, 87 F.3d 1389, 1393
(D.C. Cir. 1996) (en banc). My dissent is confined to the
majority’s compliance with that principle in its otherwise
admirable opinion. That is, I cannot agree that four of the
fourteen original Simon plaintiffs may continue with their action,
given the Supreme Court’s unanimous decision in Federal
Republic of Germany v. Philipp (Philipp III), 141 S. Ct. 703
(2021), and our decision on remand in Philipp v. Stiftung
Preussischer Kulturbesitz (Philipp VI), No. 22-7126, – F.4th –,
2023 WL 4536152 (D.C. Cir. July 14, 2023) (per curiam).

     The Philipp case, involving the Nazis taking the property of
Jews in Germany, and Simon, involving the taking of property of
Jews in Hungary, raised comparable issues under the Foreign
Sovereign Immunities Act. Our court naturally treated a
decision in one as impacting the other. See, e.g., Simon v.
Republic of Hungary (Simon II), 911 F.3d 1172, 1176 (D.C. Cir.
2018) (citing Philipp v. Federal Republic of Germany (Philipp
II), 894 F.3d 406 (D.C. Cir. 2018)). The Supreme Court did the
same. The Court granted writs of certiorari in Philipp and Simon
at the same time. See 141 S. Ct. 185 (July 2, 2020) (Philipp);
141 S. Ct. 187 (July 2, 2020) (Simon). And, as I next discuss,
when the Court released its judgments in these two cases, it tied
the cases together.

     In Philipp III, the Supreme Court – disagreeing with our
court – held unanimously that foreign states and their agencies
are immune from suits in United States courts based on “a
foreign sovereign’s taking of its own nationals’ property.” Id. at
709–10. In rendering its opinion, the Court treated the plaintiffs
in Philipp as German nationals when the Nazis confiscated their
property. See id. The Court did so even though the Philipp
plaintiffs, apparently anticipating an adverse decision, suggested
to the Court (for the first time in the litigation) that they or their
                                   2

ancestors might not have been German nationals on the relevant
date. See Philipp VI, 2023 WL 4536152, at *1. In response to
this belated claim, the Supreme Court not only vacated our
judgment in Philipp but also remanded the case for a
determination whether the Philipp plaintiffs had preserved their
new contention that they were not German nationals at the time
of the alleged takings. Philipp III, 141 S. Ct. at 715–16.

     On the same day, the Supreme Court issued the following
per curiam order in this, the Simon case: “The judgment of the
United States Court of Appeals for the D. C. Circuit is vacated,
and the case is remanded for further proceedings consistent with
the decision in [Philipp III].” Republic of Hungary v. Simon
(Simon III), 141 S. Ct. 691 (2021). The Court’s mandate thus
required, on remand, a decision whether the Simon plaintiffs, or
any one of them, had preserved a claim that they were not
Hungarian nationals when Hungary confiscated their property.
In light of the mandate, the preservation question had to be
determined because subject matter jurisdiction turned on it, at
least as a preliminary matter.1 See Arbaugh v. Y&H Corp., 546
U.S. 500, 514 (2006); Capron v. Van Noorden, 6 U.S. 126, 127
(1804) (“Here it was the duty of the Court to see that they had
jurisdiction, for the consent of parties could not give it.”).

     In the appeal in the remanded Philipp case, we determined
– in agreement with the district court – that the plaintiffs had
failed to preserve a not-German-nationals claim. Philipp VI,
2023 WL 4536152, at *2. The Simon case, also on appeal after
remand, presents an even stronger ground for reaching the same

        1
          The plaintiffs’ burden to establish jurisdiction increases at
later stages in litigation. See Lujan v. Defs. of Wildlife, 504 U.S. 555,
561 (1992).
                                  3

result with respect to the plaintiffs’ disclaimer of Hungarian
nationality.2

     As in Philipp, none of the plaintiffs in Simon alleged in their
original complaint or in either of their amended complaints that
they were nationals of a country other than Hungary at the time
of the takings. See Simon v. Republic of Hungary, 579 F. Supp.
3d 91, 124 (D.D.C. 2021), appeal dismissed, 2022 WL 7205036
(D.C. Cir. Oct. 12, 2022). The majority attempts to fill this gap
by quoting a sentence from one of the plaintiffs’ district court
memoranda from twelve years ago. Maj. Op. 30. There are two
problems with the attempt. An obvious one is that the quotation
does not alter the fact that the plaintiffs’ pleadings – their
complaint and amended complaints – never alleged that they
were Czechoslovakian nationals at the time of the alleged
takings. The second is that the plaintiffs were arguing the
opposite of what the majority thinks. That is, in the quoted
passage the plaintiffs were disputing the claim of the Hungarian
state at the start of World War II that they were no longer
“citizens” of Hungary despite the fact – as plaintiffs stated in
their preceding sentence – that the “14 Named Plaintiffs are
Holocaust survivors who lived in the Hungarian State at the
threshold of World War II.” Pls.’ Opp’n 3, 17, Simon v.
Republic of Hungary, No. 1:10-cv-01770-BAH (D.D.C. May 6,
2011), ECF No. 24.

        2
           The majority tries to distinguish Philipp. See Maj. Op.
29–30. But as the majority suggests, the Philipp plaintiffs did plead
facts that could meet the “minimum requirements” for a non-German
nationality. See Maj. Op. 30; Second Amended Complaint at ¶¶ 55,
170, Philipp v. Stiftung Preussischer Kulturbesitz No.
1:15-cv-00266-CKK (D.D.C. September 9, 2021), ECF No. 62. And
the Philipp plaintiffs did press their non-German-nationality argument
before the Supreme Court (unlike the plaintiffs here). See Philipp VI,
2023 WL 4536152, at *1.
                                  4

    As in Philipp, the Simon plaintiffs had “every opportunity”
– and indeed, every incentive – to allege in their original
complaint or in their amended complaints that they were
Czechoslovakian nationals.3 Philipp VI, 2023 WL 4536152, at
*2. But unlike the plaintiffs in Philipp, the Simon plaintiffs
never informed the Supreme Court that they even contemplated
asserting such an allegation. Instead, the Simon plaintiffs
represented to the Supreme Court in the clearest possible terms
that they were all Hungarian nationals when the takings
occurred: “All 14 of the Survivors were Hungarian nationals
during World War II but have adopted other nationalities since
escaping the atrocities of the Hungarian government.” Brief in
Opposition at 4–5, Simon III, 141 S. Ct. 691 (2021) (No. 18-
1447), 2019 WL 3380416 at *4–5. That too had been our
court’s understanding when the case reached us on appeal: “The
named plaintiffs in this case are fourteen Jewish survivors of the
Hungarian Holocaust. All fourteen were Hungarian nationals
during World War II but have since adopted other nationalities.”

        3
          The Simon plaintiffs devoted a portion of their Supreme
Court merits brief to the FSIA expropriation exception because
Hungary had “contested this question of subject matter jurisdiction
below” and “intend[ed] to reap the benefits if Germany prevail[ed]”
in the Philipp case. Brief for Respondents at 42 n.5, Simon III, 141 S.
Ct. 691 (2021) (No. 18-1447), 2020 WL 6292564 at *42 n.5; see also
Reply Brief for Appellants Rosalie Simon, et. al. at 9, Simon v.
Republic of Hungary (Simon I), 812 F.3d 127 (D.C. Cir. 2016) (No.
14-7082), 2014 WL 6603413 at *9 (“Hungary alleges that
international law is not implicated where the wrongful conduct is
perpetrated against a state’s own citizens or nationals.”); Opposition
Brief of Defendants-Appellees at 32, Simon I, 812 F.3d 127 (D.C. Cir.
2016) (No. 14-7082), 2014 WL 5795145 at *32 (no violation of
international law because “Plaintiffs were Hungarian nationals at the
time of the events in question”).
                                 5

Simon v. Republic of Hungary (Simon I), 812 F.3d 127, 134
(D.C. Cir. 2016).4

    The short of the matter is that the Simon plaintiffs, like the
plaintiffs in Philipp, did not preserve a claim that they were
nationals of a country other than Hungary when the takings
occurred. The longstanding rule of this circuit, and of the other
circuits,5 is as follows: “It is elementary that where an argument
could have been raised on an initial appeal, it is inappropriate to
consider that argument on a second appeal following remand.”
Northwestern Indiana Tel. Co. v. F.C.C., 872 F.2d 465, 470
(D.C. Cir. 1989) (quoted in United States v. Henry, 472 F.3d
910, 913 (D.C. Cir. 2007)). As we held in Philipp, in order to
“preserve a claim, a party must raise it ‘squarely and distinctly.’”
Philipp, 2023 WL 4536152, at *2 (quoting Bronner on Behalf of
Am. Stud. Ass’n v. Duggan, 962 F.3d 596, 611 (D.C. Cir. 2020)).
The Simon plaintiffs did neither.

        4
         The plaintiffs argued that Article 27 of the 1947 Peace
Treaty applied to them because they were Hungarian nationals when
Hungary took their property. See Reply Brief for Appellants Rosalie
Simon, et. al. at 3, Simon I, 812 F.3d 127 (D.C. Cir. 2016) (No.
14-7082), 2014 WL 6603413 at *3.
        5
          See, e.g., Omni Outdoor Advert., Inc. v. Columbia Outdoor
Advert., Inc., 974 F.2d 502, 505 (4th Cir. 1992); United States v.
Morris, 259 F.3d 894, 898 (7th Cir. 2001); Christian Legal Soc’y
Chapter of Univ. Of Cal. v. Wu, 626 F.3d 483, 486–88 (9th Cir. 2010).