See z.B. Andrew T. Guzman, Saving Customary International Law, 27 J. Int`l L. 115, 124-28 (2005) (Debate on Uncertainties Related to Customary International Law). See also Hamdan v. United States, 696 F.3d 1238, 1250 (D.C. Cir. 2012) (Kavanaugh, J.) (“It is often difficult to determine what constitutes the customary law of the peoples, which defines international customary law, and how firmly a standard must be entrenched in order to be considered a standard of habit of peoples.”) who were repealed for unrelated reasons of Al Bahlul against the United States, 767 F.3d 1 (D.C. Cir. 2014) (in bench).
See z.B. Garamendi, 539 U.S. at 415 (discussion of the “Executive Agreements to Settle the Rights of U.S. Nationals Against Foreign Governments” from 1799); Act of February 20, 1792, No. 26, 1 Stat. 239 (law passed by the Second Congress for the approval of post-linked executive agreements). Dependence on contractual power has declined since World War II, as presidents increasingly turn to the use of executive agreements as a means of ensuring unilateral control of U.S. foreign relations.
If the president acts unilaterally, the agreement is called a “single executive agreement.” If the president acts with the agreement of a simple majority of both houses of Congress, the agreement is called “legislative and executive agreement.” Presidents have a “margin of appreciation” in deciding whether they wish to pursue an international agreement in the form of a treaty, a single executive agreement or in the form of a legislative and executive agreement. The Speaker`s decision generally depends on political factors, including the likelihood of obtaining Senate approval. Presidents have often chosen to exclude the Senate from concluding some controversial and historic international pacts on the channel of executive agreements, including the basic destructive agreement with Britain in 1940, the Yalta and Potsdam accords of 1945, the Vietnam Peace Agreement of 1973 and the Sinai Accords of 1975. Some foreign relations experts have recently argued that the practice of the international agreement has developed so that some modern executive agreements no longer fit into the three generally accepted categories of executive agreements69. who argue for a new form of executive agreement arguing that it is not necessary to determine a specific authorisation status or constitutional power if the President already has the national power to implement the executive agreement; The agreement does not require any changes to national legislation; 71 Opponents of this proposed new paradigm of the executive agreement argue that it is not compatible with the principles of separation of powers, which they believe require the President to authorize the conclusion of international agreements either by the Constitution, by a ratified treaty or by an act of Congress. Despite the complexity of the doctrine of internal self-enforcement, treaties and other international agreements that operate in two international and domestic legal contexts.126 In the international context, international agreements are traditionally binding pacts between sovereign nations and create rights and duties which, in accordance with international law, are rights and obligations which, under international law, are , owed to each other.127 However, international law generally allows each nation to decide how it should implement its contractual obligations in its own national legal system128 The doctrine of self-enforcement concerns the determination of treaties. is being implemented in the United States.