(Slip Opinion) OCTOBER TERM, 2022 1 

Syllabus 

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is 

being done in connection with this case, at the time the opinion is issued. 

The syllabus constitutes no part of the opinion of the Court but has been 

prepared by the Reporter of Decisions for the convenience of the reader. 

See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337. 

SUPREME COURT OF THE UNITED STATES 

Syllabus 

NEW YORK v. NEW JERSEY 

ON CROSS-MOTIONS FOR JUDGMENT ON THE PLEADINGS 

No. 156, Orig. Argued March 1, 2023—Decided April 18, 2023 

In 1953, New York and New Jersey exercised their authority under 

Article I, §10, of the Constitution to enter into a compact to address

corruption at the Port of New York and New Jersey. The Waterfront 

Commission Compact established a bistate agency known as the 

Waterfront Commission of New York Harbor, to which the States 

delegated their sovereign authority to conduct regulatory and lawenforcement activities at the Port. The Compact does not address each

State’s power to withdraw from the Compact. 

In 2018, New Jersey sought to unilaterally withdraw from the 

Compact, over New York’s opposition. New York filed a bill of 

complaint in this Court, and the parties then filed cross-motions for

judgment on the pleadings, with the United States supporting New

Jersey as amicus curiae. 

Held: New Jersey may unilaterally withdraw from the Waterfront 

Commission Compact notwithstanding New York’s opposition. Pp. 3–

9. 

(a) The interpretation of an interstate compact approved by 

Congress presents a federal question, see Cuyler v. Adams, 449 U. S. 

433, 438, the resolution of which begins with an examination of “the 

express terms of the Compact,” Tarrant Regional Water Dist. v. 

Herrmann, 569 U. S. 614, 628. Unlike certain other compacts, the 

Compact here does not address withdrawal.

Because the Compact is silent as to unilateral withdrawal, the Court 

looks to background principles of law that would have informed the

parties’ understanding when they entered the Compact. As relevant 

here, interstate compacts “are construed as contracts under the 

principles of contract law.” Ibid. Under the default contract-law rule 

at the time of the Compact’s formation, a contract that contemplates 

“continuing performance for an indefinite time is to be interpreted as 
 

 

 

2 NEW YORK v. NEW JERSEY 

Syllabus 

stipulating only for performance terminable at the will of either party.” 

1 R. Lord, Williston on Contracts §4:23, p. 570. Here, the States 

delegated their sovereign authority to the Commission on an ongoing 

and indefinite basis. The default contract-law rule therefore “speaks

in the silence of the Compact” and indicates that either State may 

unilaterally withdraw. New Jersey v. New York, 523 U. S. 767, 784. 

Principles of state sovereignty also support New Jersey’s position. 

“The background notion that a State does not easily cede its 

sovereignty has informed” this Court’s “interpretation of interstate

compacts.” Tarrant, 569 U. S., at 631. The nature of the delegation at

issue here—delegation of a State’s sovereign power to protect the

people, property, and economic activity within its borders—buttresses

the conclusion that New Jersey can unilaterally withdraw. 

To be clear, the contract-law rule that governs the Compact here 

does not apply to other kinds of compacts that do not exclusively call 

for ongoing performance on an indefinite basis—such as compacts

setting boundaries, apportioning water rights, or otherwise conveying 

property interests. Pp. 3–7.

(b) New York’s additional arguments in support of its view that the

Compact should be read to prohibit unilateral withdrawal are 

unpersuasive. First, New York argues that the Court should interpret

the 1953 Compact in light of pre-1953 compacts that were silent on 

unilateral withdrawal but were understood to forbid it. But many of

those compacts concerned boundaries and water-rights allocation—the

very kinds of compacts that are not governed by the default contractlaw rule authorizing unilateral withdrawal. Second, New York 

invokes international treaty law, which New York says generally 

prohibits a signatory nation’s unilateral withdrawal from a treaty

absent express language otherwise. But international treaty practice, 

to the extent it is relevant here, is equivocal. Third, New York points 

to the past practice of the States’ resolving Commission-related 

disputes. But that practice says little about whether either State could

unilaterally withdraw. Fourth, New York maintains that the Court’s 

decision will have sweeping consequences for interstate compacts 

generally. But the Court’s decision does not address all compacts, and

States may propose language to compacts expressly allowing or

prohibiting unilateral withdrawal. Pp. 7–9. 

New Jersey’s motion for judgment on the pleadings granted; New York’s 

cross-motion for judgment on the pleadings denied. 

KAVANAUGH, J., delivered the opinion for a unanimous Court. 
Cite as: 598 U. S. ____ (2023) 1 

Opinion of the Court 

NOTICE: This opinion is subject to formal revision before publication in the 

United States Reports. Readers are requested to notify the Reporter of 

Decisions, Supreme Court of the United States, Washington, D. C. 20543, 

pio@supremecourt.gov, of any typographical or other formal errors. 

SUPREME COURT OF THE UNITED STATES _________________ 

No. 156, Orig. 

_________________ 

NEW YORK v. NEW JERSEY 

ON CROSS-MOTIONS FOR JUDGMENT ON THE PLEADINGS

[April 18, 2023]

 JUSTICE KAVANAUGH delivered the opinion of the Court. 

 Under Article I, §10, of the Constitution, each State 

possesses the sovereign authority to enter into a compact 

with another State, subject to Congress’s approval. In 

1953, New York and New Jersey exercised that authority 

and entered into the Waterfront Commission Compact. The 

Compact created a bistate agency to perform certain 

regulatory and law-enforcement functions at the Port of 

New York and New Jersey. In 2018, after concluding that 

the decades-old Compact had outlived its usefulness, New 

Jersey sought to withdraw from the Compact. New York 

opposes New Jersey’s withdrawal and contends that the 

Compact does not allow either State to unilaterally 

withdraw. We hold that New Jersey may unilaterally 

withdraw from the Waterfront Commission Compact 

notwithstanding New York’s opposition. 

I 

 In 1951, New York and New Jersey began a joint 

investigation of organized crime at the Port of New York 

and New Jersey, a commercial port that spans the border of 

the two States. To address corruption within the labor force 

on both sides of the Port, each State enacted legislation to 

form the Waterfront Commission Compact. See 1953 N. J. 
 

 

2 NEW YORK v. NEW JERSEY 

Opinion of the Court 

Laws p. 1511; 1953 N. Y. Laws p. 2417. New York and New 

Jersey obtained Congress’s approval of the Compact in

1953, consistent with the Compact Clause of the 

Constitution. President Eisenhower signed the Compact.

See 67 Stat. 541; U. S. Const., Art. I, §10, cl. 3.

The Compact established a bistate agency known as the

Waterfront Commission of New York Harbor. The 

Commission consists of two members, one appointed by the

Governor of New York and the other by the Governor of 

New Jersey. Through the Compact, New York and New 

Jersey delegated to the Commission their sovereign

authority to conduct regulatory and law-enforcement

activities at the Port. For example, the Compact authorizes 

the Commission to oversee mandatory employment

licensing for waterfront workers and to conduct lawenforcement investigations at the Port.

Under the Compact, New York and New Jersey must

agree if they want to make any “[a]mendments and 

supplements.” Art. XVI(1), 67 Stat. 557. The Compact also

recognizes Congress’s authority to “alter, amend, or repeal” 

the Compact. Art. XVI, §2, ibid. But the Compact does not

address each State’s power to unilaterally withdraw: It 

neither expressly allows nor expressly proscribes unilateral

withdrawal. 

The Compact and Commission have operated for 70 

years. But as the decades have passed, circumstances at 

the Port have changed. In 1953, roughly 70% of waterfront

employees worked on the New York side of the Port. But 

by 2018, according to New Jersey, more than 80% of work 

hours occurred on the New Jersey side, and more than 80%

of the Port’s cargo flowed through the New Jersey side. 

New Jersey also came to view the Commission as illequipped to handle 21st-century security challenges and as

a source of overregulation that impedes job growth. 

In 2018, the New Jersey Legislature passed and

Governor Christie signed a law to withdraw New Jersey 
 

Cite as: 598 U. S. ____ (2023) 3 

Opinion of the Court 

from the Waterfront Commission Compact. See 2017 N. J. 

Laws p. 2102. The statute required the New Jersey

Governor to give 90 days’ notice of the State’s intention to 

withdraw. Upon withdrawal, the Commission would 

dissolve, and the New Jersey State Police would take over 

the Commission’s law-enforcement functions on the New 

Jersey side of the Port.

The day after enactment of the withdrawal statute, the 

Commission sued in Federal District Court to stop New 

Jersey from unilaterally withdrawing from the Compact.

The District Court ruled that New Jersey could not 

unilaterally withdraw. Waterfront Comm’n of N. Y. Harbor 

v. Murphy, 429 F. Supp. 3d 1 (NJ 2019). But the U. S. 

Court of Appeals for the Third Circuit reversed and ruled

in New Jersey’s favor, determining that state sovereign 

immunity barred the Commission’s lawsuit. Waterfront 

Comm’n of N. Y. Harbor v. Governor of New Jersey, 961 

F. 3d 234 (2020).

In 2021, in the wake of the Third Circuit’s decision, 

Acting Governor Oliver announced New Jersey’s intent to

unilaterally withdraw from the Compact. Before the 

expected date of withdrawal, New York moved in this Court

for leave to file a bill of complaint and for a temporary order 

preventing New Jersey’s withdrawal. This Court 

temporarily enjoined New Jersey from withdrawing from 

the Compact pending final disposition of this case. The 

Court later granted New York’s motion for leave to file a bill

of complaint and allowed the parties to file cross-motions 

for judgment on the pleadings. In this Court, the United 

States also participated as amicus curiae in support of New 

Jersey’s unilateral withdrawal from the Compact. 

II 

The question presented is straightforward: Does the 

Waterfront Commission Compact allow New Jersey to

unilaterally withdraw from the Compact notwithstanding 
 

 

4 NEW YORK v. NEW JERSEY 

Opinion of the Court 

New York’s opposition? The answer is yes.

The interpretation of the Waterfront Commission 

Compact—an interstate compact approved by Congress—

presents a federal question. See Cuyler v. Adams, 449 U. S. 

433, 438 (1981). To resolve the dispute over whether each

State may unilaterally withdraw, we “begin by examining 

the express terms of the Compact as the best indication of

the intent of the parties.” Tarrant Regional Water Dist. v. 

Herrmann, 569 U. S. 614, 628 (2013). 

Some interstate compacts expressly allow, prohibit, or

limit unilateral withdrawal.1 But this Compact does not 

address withdrawal. The Compact mentions neither 

“withdrawal” nor “termination” in any relevant context.

The Compact provides for amendments, which require both

States to agree. See Art. XVI(1), 67 Stat. 557. But 

unilateral withdrawal does not constitute an amendment to 

the Compact and thus does not implicate the amendment 

provision. The Compact also authorizes Congress to “alter,

amend, or repeal” the Compact. See Art. XVI, §2, ibid. But 

Congress did not retain an exclusive right to terminate the 

Compact.

Because the Compact’s text does not address whether a

State may unilaterally withdraw, we look to background

principles of law that would have informed the parties’

understanding when they entered the Compact. This Court 

has long explained that interstate compacts “are construed 

as contracts under the principles of contract law.” Tarrant, 

—————— 1See, e.g., Central Interstate Low-Level Radioactive Waste Compact, 

Art. VII(d), 99 Stat. 1870 (1986) (expressly allowing unilateral 

withdrawal); Snake River Compact, Art. XII, 64 Stat. 33 (1950)

(expressly providing that the compact will remain in force unless 

terminated by both state legislatures and consented to by Congress); 

New York-New Jersey Port Authority Compact, Art. 21, 42 Stat. 179

(1921) (expressly allowing unilateral withdrawal within two years of the

compact’s formation); Delaware River Basin Compact, Art. 1, §1.6(a), 75 

Stat. 691 (1961) (expressly allowing unilateral termination only after 100

years). 
 

Cite as: 598 U. S. ____ (2023) 5 

Opinion of the Court 

569 U. S., at 628; see also Alabama v. North Carolina, 560 

U. S. 330, 359 (2010) (Kennedy, J., concurring in part and 

concurring in judgment); Texas v. New Mexico, 482 U. S. 

124, 128–129 (1987); Green v. Biddle, 8 Wheat. 1, 92 (1823). 

To that end, the Court has looked to “background principles 

of contract law” to interpret compacts that are silent on a 

particular issue. Mississippi v. Tennessee, 595 U. S. ___, 

___ (2021) (slip op., at 10); see Tarrant, 569 U. S., at 628, 

633. 

To be sure, background rules of contract interpretation

may not override a compact’s terms. Alabama, 560 U. S., 

at 351–352. This Court has said that a compact “is not just 

a contract,” but also “a federal statute enacted by Congress” 

that preempts contrary state law. Id., at 351; see Tarrant, 

569 U. S., at 627, n. 8. But when the compact does not

speak to a disputed issue, background contract-law 

principles have informed the Court’s analysis.

Under the default contract-law rule at the time of the 

Compact’s 1953 formation, as well as today, a contract (like

this Compact) that contemplates “continuing performance 

for an indefinite time is to be interpreted as stipulating only

for performance terminable at the will of either party.” 1 

R. Lord, Williston on Contracts §4:23, p. 570 (4th ed. 2022); 

see also, e.g., Restatement (Second) of Contracts §33,

Comment d, p. 94 (1979); 1 S. Williston, Law of Contracts 

§38, p. 59 (1920); Compania Embotelladora Del Pacifico, 

S. A. v. Pepsi Cola Co., 976 F. 3d 239, 245 (CA2 2020); In re 

Miller’s Estate, 90 N. J. 210, 219, 447 A. 2d 549, 554 (1982); 

Zimco Restaurants, Inc. v. Bartenders and Culinary 

Workers Union, Local 340, 165 Cal. App. 2d 235, 240 (1958); 

Fulghum v. Selma, 238 N. C. 100, 103–104, 76 S. E. 2d 368, 

370–371 (1953); Bailey v. S. S. Stafford, Inc., 178 App. Div. 

811, 815, 166 N. Y. S. 79, 82 (1917). Parties to a contract 

that calls for ongoing and indefinite performance generally 

need not continue performance after the contractual 

relationship has soured, or when the circumstances that 
 

 

6 NEW YORK v. NEW JERSEY 

Opinion of the Court 

originally motivated the agreement’s formation have

changed, for example. See Delta Servs. & Equip., Inc. v. 

Ryko Mfg. Co., 908 F. 2d 7, 11 (CA5 1990); Jespersen v. 

Minnesota Min. & Mfg. Co., 183 Ill. 2d 290, 295, 700 N. E. 

2d 1014, 1017 (1998).

That default contract-law rule—that contracts calling for 

ongoing and indefinite performance may be terminated by

either party—supports New Jersey’s position in this case.

Through the Waterfront Commission Compact, New York 

and New Jersey delegated their sovereign authority to the

Commission on an ongoing and indefinite basis. And the 

Compact contemplates the Commission’s exercise of that

authority on an ongoing and indefinite basis. The default 

contract-law rule therefore “speaks in the silence of the 

Compact” and indicates that either State may unilaterally

withdraw. New Jersey v. New York, 523 U. S. 767, 784 

(1998).

Principles of state sovereignty likewise support New 

Jersey’s position. “The background notion that a State does 

not easily cede its sovereignty has informed our 

interpretation of interstate compacts.” Tarrant, 569 U. S., 

at 631. Here, the Compact involves the delegation of a 

fundamental aspect of a State’s sovereign power—its ability 

to protect the people, property, and economic activity within

its borders—to a bistate agency. The nature of that 

delegation buttresses our conclusion that New York and 

New Jersey did not permanently give up, absent the States’ 

joint consent or congressional action to terminate the 

Compact, their authority to withdraw from the Compact

and to exercise those sovereign police powers at the Port as 

each State sees fit. 

We draw further guidance from the fact that, as is 

undisputed, New York and New Jersey never intended for

the Compact and Commission to operate forever. See Brief 

for New York 19, 26; Brief for New Jersey 33, n. 8; Tr. of 

Oral Arg. 69, 100–101. Given that the States did not intend 
Cite as: 598 U. S. ____ (2023) 7 

Opinion of the Court 

for the agreement to be perpetual, it would not make much 

sense to conclude that each State implicitly conferred on the

other a perpetual veto of withdrawal.

In sum, background principles of contract law, reinforced

here by principles of state sovereignty and the fact that the 

States did not intend for the Compact to operate forever,

indicate that New Jersey may unilaterally withdraw from

the Waterfront Commission Compact. To be clear, the 

contract-law rule that we apply today governs compacts 

(like this Compact) that are silent as to unilateral 

withdrawal and that exclusively call for ongoing 

performance on an indefinite basis. But that rule does not 

apply to other kinds of compacts that do not exclusively call 

for ongoing performance on an indefinite basis—such as 

compacts setting boundaries, apportioning water rights, or 

otherwise conveying property interests. Both New York 

and New Jersey agree that States may not unilaterally 

withdraw from compacts that are silent as to withdrawal 

and that set boundaries, apportion water rights, or

otherwise convey property interests. See Brief for New 

York 3–4, 30, 38; Brief for New Jersey 27–29; Tr. of Oral

Arg. 30, 44, 55. 

III 

New York advances several additional arguments in

support of its view that the Compact nonetheless should be

read to prohibit unilateral withdrawal. But none is 

persuasive. 

First, New York invokes the history of compacts before 

1953. In New York’s view, many pre-1953 compacts were 

silent on unilateral withdrawal but nonetheless were 

understood to forbid it. New York says that when States at 

that time wanted to allow unilateral withdrawal, the 

compacts would expressly provide for it. And New York 

adds that we should interpret the 1953 Compact in light of 

that practice. 
 

 

8 NEW YORK v. NEW JERSEY 

Opinion of the Court 

As New York acknowledges, however, many of those pre1953 compacts concerned boundaries and water-rights 

allocation. See Brief for New York 3–4, 30; Tr. of Oral Arg.

30, 33. Those compacts, as we have explained, are not

governed by the default contract-law rule authorizing

unilateral withdrawal. New York offers no persuasive

evidence that the background understanding of withdrawal 

from boundary and water-rights compacts also applied to 

compacts that exclusively call for ongoing performance on

an indefinite basis by an interstate agency. Indeed, just 

three years before the Compact here was formed, the

United States explained to this Court that a compacting

State could unilaterally withdraw from a compact that was

silent as to withdrawal and that required an ongoing and 

indefinite exercise of sovereign authority. See Brief for 

United States in West Virginia ex rel. Dyer v. Sims, O. T. 

1950, No. 147, pp. 23–24, 26–27. In addition, New York 

overlooks that some compacts, including one formed three 

years before this Compact, expressly prohibited unilateral

withdrawal. See Snake River Compact, Art. XII, 64 Stat. 

33; see also, e.g., Goose Lake Basin Compact, Arts. V, 

VII(B), 98 Stat. 292 (1984). That language would have been

unnecessary if New York were correct about the pre-1953

practice.

In short, New York identifies no clear historical practice

in support of its view that compacts calling for ongoing and 

indefinite performance and that were silent on withdrawal 

were understood as of 1953 to prohibit unilateral 

withdrawal. 

Second, New York invokes international treaty law.

According to New York, international law generally 

prohibits a signatory nation’s unilateral withdrawal from a 

treaty absent express language otherwise. But to the 

extent that international treaty practice is relevant here, it 

is equivocal. Scholars have “long debated” whether nations

may unilaterally withdraw from treaties that do not 
Cite as: 598 U. S. ____ (2023) 9 

Opinion of the Court 

expressly authorize withdrawal. L. Helfer, Exiting

Treaties, 91 Va. L. Rev. 1579, 1592 (2005). And although 

the Vienna Convention on the Law of Treaties (to which the

United States is not a party) provides that nations 

generally may not withdraw from a treaty absent express 

authorization, the Convention acknowledges that the

nature of the treaty may nonetheless imply a right of 

withdrawal. Art. 56(1), May 23, 1969, 1155 U. N. T. S. 331; 

see also J. Brierly, The Law of Nations 240 (4th ed. 1949). 

Third, New York points out that New York and New 

Jersey have resolved Commission-related disputes in the 

decades since 1953. According to New York, that practice 

suggests that the Compact prohibits unilateral withdrawal. 

But the States’ past success in resolving disputes says little

about whether New York or New Jersey could unilaterally 

withdraw if and when either State wanted to do so. 

Fourth, New York argues that allowing New Jersey to

withdraw would have sweeping consequences for interstate

compacts generally. But our decision today only addresses 

a compact that (i) is silent on unilateral withdrawal; 

(ii) calls for ongoing and indefinite performance; and

(iii) does not set boundaries, apportion water rights, or 

otherwise convey property interests. Moreover, for any

current and future compacts, States can propose language 

expressly allowing or prohibiting unilateral withdrawal if 

they wish to do so. 

* * * 

New Jersey may unilaterally withdraw from the 

Waterfront Commission Compact notwithstanding New 

York’s opposition. We therefore grant New Jersey’s motion 

for judgment on the pleadings and deny New York’s crossmotion. 

It is so ordered.