<P> Between 1946 and 1999, the United States completed nearly 16,000 international agreements . Only 912 of those agreements were treaties, submitted to the Senate for approval as outlined in Article II of the United States Constitution . Since the Franklin Roosevelt presidency, only 6% of international accords have been completed as Article II treaties . Most of these executive agreements consist of congressional - executive agreements . </P> <P> American law is that international accords become part of the body of U.S. federal law . Consequently, Congress can modify or repeal treaties by subsequent legislative action, even if this amounts to a violation of the treaty under international law . This was held, for instance, in the Head Money Cases . The most recent changes will be enforced by U.S. courts entirely independent of whether the international community still considers the old treaty obligations binding upon the U.S. </P> <P> Additionally, an international accord that is inconsistent with the U.S. Constitution is void under domestic U.S. law, the same as any other federal law in conflict with the Constitution . This principle was most clearly established in the case of Reid v. Covert . The Supreme Court could rule an Article II treaty provision to be unconstitutional and void under domestic law, although it has not yet done so . </P> <P> In Goldwater v. Carter, Congress challenged the constitutionality of then - president Jimmy Carter's unilateral termination of a defense treaty . The case went before the Supreme Court and was never heard; a majority of six Justices ruled that the case should be dismissed without hearing an oral argument, holding that "The issue at hand...was essentially a political question and could not be reviewed by the court, as Congress had not issued a formal opposition ." In his opinion, Justice Brennan dissented, "The issue of decision making authority must be resolved as a matter of constitutional law, not political discretion; accordingly, it falls within the competence of the courts". Presently, there is no official Supreme Court ruling on whether the President has the power to break a treaty without the approval of Congress, and the courts also declined to interfere when President George W. Bush unilaterally withdrew the United States from the ABM Treaty in 2002, six months after giving the required notice of intent . </P>

Do treaties have to comply with the constitution