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U.S. Foreign Policy Powers: Congress and the President
The U.S. Constitution parcels out foreign relations powers to both the executive and legislative branches. It grants some powers, like command of the military, exclusively to the president and others, like the regulation of foreign commerce, to Congress, while still others it divides among the two or simply does not assign.
“The Constitution, considered only for its affirmative grants of power capable of affecting the issue, is an invitation to struggle for the privilege of directing American foreign policy,” wrote
constitutional scholar Edward S. Corwin in 1958.
The periodic tug-of-war between the president and Congress over foreign policy is not a by-product of the Constitution, but rather, one of its core aims.
Article I of the Constitution enumerates several of Congress’s foreign affairs powers, including those to “regulate commerce with foreign nations,” “declare war,” “raise and support armies,” “provide and maintain a navy,” and “make rules for the government and regulation of the land and naval forces.” The Constitution also makes two of the president’s foreign affairs powers—making treaties and appointing diplomats—dependent on Senate approval.