In the United States, executive agreements are binding internationally when negotiated and concluded under the authority of the president on foreign policy, commander-in-chief of the armed forces, or a previous act of Congress. For example, the president, as commander-in-chief, negotiates and enters into status of forces agreements (SOFAs) governing the treatment and disposition of U.S. armed forces stationed in other nations. However, the President may not unilaterally conclude executive agreements on matters not within his constitutional authority. In such cases, an agreement should take the form of an agreement between Congress and the executive or a contract with deliberation and approval by the Senate.  A treaty-based executive agreement, to the extent that it falls within the intent, scope and purpose of the parent contract, has the same validity and effect as the contract itself and is subject to the same constitutional restrictions. Derived from one of the elements of the “supreme law of the land,” it prevails over all inconsistent state laws and follows the usual rule that favors the instrument later in the event of inconsistency with a federal law. A striking example of a contract-based executive agreement is the traditional compromise, which defines the conditions for submission to a decision or arbitration under a basic agreement. Another is found in the hundreds of status-of-forces agreements and other agreements necessary for the implementation of the North Atlantic Treaty, the linchpin of U.S.
policy in Europe since World War II. A treaty is an international agreement concluded in writing between two or more sovereign States and subject to international law, whether enshrined in a single legal act or in two or more related instruments. Treaties have many names: conventions, agreements, alliances, pacts, charters and statutes, among others. The choice of name has no legal significance. Contracts generally fall into one of two broad categories: bilateral (between two countries) and multilateral (between three or more countries). Britannica.com: Encyclopedia articles on the executive agreement In summary, all three categories of executive agreements have a historical tendency towards strong executive leadership in foreign policy. Just add three last points. First, the cessation of the use of these agreements instead of the contractual alternative is essentially politically influenced by environmental circumstances rather than abstract legal theories. Second, once in force, executive agreements are likely to be binding on the United States and other parties under international law, to the same extent and in the same manner as treaties. Thirdly, international commitments under such agreements survive any subsequent restrictions or restrictions of national law. Second, while it is generally accepted that, pursuant to the “executive power” clause, the President has the power to enter into single executive agreements that are not inconsistent with legislation in areas where the primary responsibility rests with Congress, the question arises as to whether the President may enter into an agreement alone that is inconsistent with an act of Congress, or alternatively, whether a single executive agreement can replace previous inconsistent laws of Congress. The prevailing view, rooted in the belief that it would be ruthless to repeal an act of Congress for an act of a single person – the president – is that the only executive agreements in the United States are ineffective as law, insofar as they conflict with an earlier act of Congress in an area of competence in Congress.
. . .