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
