Debate over who has the authority to make foreign policy for the United States has been a constant feature of our political and constitutional history. In the modern era, the debate has come to be both shrill and stale: the proponents of presidential autonomy and the advocates of congressional supremacy start from mutually incompatible premises and come to predictable, and antagonistic, conclusions. The President’s Authority Over Foreign Affairs argues that the best interpretation of our Constitution’s distribution of foreign affairs authority resolves this irresolvable stand-off. Powell presents a traditional legal argument, giving careful weight to original understandings, early practice and considerations of institutional structure, and concludes that the Constitution vests the president with the clear authority to formulate and implement foreign policy. At the same time, the Constitution vests Congress with powers that enable it to exercise a near-absolute veto — not on the president’s foreign policy choices, but on his or her ability to carry those choices out. The resulting system of interlocking constitutional powers is faithful to the Constitution’s text and to the purposes that are embodied in it. In making this argument, a variety of hotly contested issues are addressed, and Powell shows how constitutional interpretation enables us to reach satisfactory answers.