The presidents have also reaffirmed the power to unilaterally withdraw from agreements between Congress and the executive branch, but there is a scientific debate about the extent to which the Constitution allows the president to act in such circumstances without legislative approval. Some scholars claim that the president has the power, unilaterally withdrawing from the executive agreements of Congress, although he is not allowed to end the domestic effects of a law implementing laws.194 But others argue that Congress must approve the end of executive agreements that confer exclusive powers on Congress, such as power over international trade. , and which have obtained congressional approval after being concluded by the executive branch.195 Although this debate is still developing.195 Although this debate is still developing. The president`s unilateral end to the executive agreements of Congress has not been the subject of much litigation, and previous studies have concluded that such denunciation has not resulted in much legislative opposition.196 Some international law experts have sometimes criticized the Senate`s use of certain reservations, agreements and statements (RUDs). conflict with the “object and purpose” of a contract. RUDs that indicate that some or all of the provisions of a contract are not self-sustaining (i.e., require enforcement laws to have enforceable internal legal effects are constitutionally accepted.37 Most executive agreements were concluded on the basis of a contract or deed of Congress. However, presidents have sometimes reached executive agreements to achieve goals that would not find the support of two-thirds of the Senate. For example, after the outbreak of World War II, but before the Americans entered the conflict, President Franklin D. Roosevelt negotiated an executive agreement that gave the United Kingdom 50 obsolete destroyers in exchange for 99-year leases on some British naval bases in the Atlantic. Unlike the executive contract termination procedure, which has not received much opposition from Congress in the past, constitutional requirements to end Senate-approved ratified treaties have been the subject of occasional debate between the legislature and the executive branch. Some commentators have argued that termination of contracts is analogous to the end of federal laws.197 Since national statutes can only be terminated by the same procedure, In 1998 – that is, by a majority vote in both houses and by the signature of the president or a veto – these commentators argue that treaties must also be terminated by a procedure similar to their creation and which includes the legislative branch.199 national constitutions for the ratification of money treaties.