Executive agreements are a common tool used by presidents and heads of state to establish diplomatic and trade relations with other countries. These agreements are often used to bypass the traditional treaty-making process, which can be lengthy and politically contentious. However, there is some controversy over whether these agreements are considered formal or informal under international law.

The short answer is that executive agreements can be either formal or informal, depending on the circumstances. Formal executive agreements are those that are negotiated and ratified in accordance with established legal procedures, such as through the advice and consent of the Senate. These agreements carry the full force of law and are binding on all parties under international law. Examples of formal executive agreements include the North Atlantic Treaty of 1949 and the Geneva Conventions of 1949.

Informal executive agreements, on the other hand, are those that are not subject to the same legal procedures and do not require ratification by the Senate. These agreements may take the form of executive orders, proclamations, or even informal letters or statements between heads of state. While they may be considered legally binding under certain circumstances, informal executive agreements are generally considered less formal and less enforceable than formal agreements.

There is some debate among legal scholars over the scope and authority of informal executive agreements. Some argue that they are no less binding than formal agreements, as long as they are made in good faith and with the intention of creating a binding obligation. Others argue that informal agreements are subject to a higher degree of scrutiny and may be more easily challenged or overturned in court.

Ultimately, whether an executive agreement is considered formal or informal depends on a variety of factors, including the language and context of the agreement, the intentions of the parties, and the legal framework governing the agreement. As such, it is important for policymakers and legal professionals to carefully consider the implications of any executive agreement before entering into it, and to ensure that all parties are aware of their respective rights and obligations under international law.