Document ID: ./input/supremecourt_opinions/opinions/22pdf/21-1450_5468.pdf
Page Number: 26

Cite as:  598 U. S. ____ (2023) 

7 

GORSUCH, J., concurring in part and dissenting in part
Opinion of GORSUCH, J. 

customary  international  law  as  federal  law  when  it  enu-
merates  sources  of  “the  supreme  Law  of  the  Land.”    And 
Article I vests Congress rather than the Judiciary with the
power to “define and punish . . . Offences against the Law
of Nations.”  §8, cl. 10.  See Sosa v. Alvarez-Machain, 542 
U. S. 692, 739–742 (2004) (Scalia, J., concurring in part and 
concurring  in  judgment);  Jesner  v.  Arab  Bank,  PLC,  584 
U. S. ___, ___–___ (2018) (GORSUCH, J., concurring in part 
and concurring in judgment) (slip op., at 4–5); Nestlé USA, 
Inc. v. Doe, 593 U. S. ___, ___ (2021) (GORSUCH, J., concur-
ring) (slip op., at 3).

Perhaps Article III incorporated customary international 
law  into  federal  common  law.  But  since  Erie  R. Co.  v. 
Tompkins, 304 U. S. 64 (1938), federal courts have largely 
disclaimed  the  power  to  develop  federal  common  law  out-
side of a few reserved areas.  See Sosa, 542 U. S., at 740– 
742 (opinion of Scalia, J.).  And whether customary inter-
national law survives as a form of federal common law after 
Erie  is  a  matter  of  considerable  debate  among  scholars.
Compare  C.  Bradley  &  J.  Goldsmith,  Customary  Interna-
tional Law as Federal Common Law:  A Critique of the Mod-
ern Position, 110 Harv. L. Rev. 815 (1997), with H. Koh, Is
International  Law  Really  State  Law?,  111  Harv.  L. Rev. 
1824 (1998).  Must lower courts confront this long-running
debate to resolve a claim of foreign sovereign immunity in
criminal cases?  And if there is no federal law at work here 
that might apply under the Supremacy Clause, only general 
common-law  principles,  what  constraints  remain  on  state 
prosecutions of foreign sovereigns? 

* 
Today’s decision overcomplicates the law for no good rea-
son.  In the FSIA, Congress supplied us with simple rules 
for  resolving  this  case  and  others  like  it.    Respectfully,  I
would follow those straightforward directions to the same
straightforward  conclusion  the  Second  Circuit  reached: 
This case against Halkbank may proceed.