The Times comments that -
Professor Henkin, unusual in combining equal expertise in constitutional law and international law, moved easily between academia and government. His legal scholarship was a fundamental resource for other scholars involved in human rights and international law, and his books addressed to a broader audience — notably Foreign Affairs and the Constitution, The Rights of Man Today, How Nations Behave and The Age of Rights — became required reading for government officials and diplomats.
Through his teaching at Columbia University, where he founded the Center for the Study of Human Rights in 1978 and the Human Rights Institute in 1998, and through seminars run by the Aspen Institute's Justice and Society Program, he trained hundreds of legal specialists and advocates in the field of human rights law.
"It is no exaggeration to say that no American was more instrumental in the development of human rights law than Lou", said Elisa Massimino, the president and chief executive officer of Human Rights First, an organization Professor Henkin helped found in 1978 under the name Lawyers' Committee for Human Rights. "He literally and figuratively wrote the book on human rights." ...
[H]e served as a law clerk for Justice Felix Frankfurter of the United States Supreme Court.
Mr. Henkin, an ardent New Dealer, worked for the State Department's United Nations bureau and its Office of European Regional Affairs from 1948 to 1956. He played a main role in negotiating the United Nation’s 1951 Refugee Convention, which set forth the standards defining refugees, their rights and the legal obligations of nations toward them.
In 1956 he was invited by Columbia University to spend a year studying the legal issues involved in the control and verification of nuclear weapons, the subject of his first book, Arms Control and Inspection in American Law (1958).
Several works on law, foreign policy and diplomacy followed, including The Berlin Crisis and the United Nations (1959) and Disarmament: The Lawyer's Interests (1964).
After teaching law at the University of Pennsylvania for five years beginning in 1958, he returned to Columbia, where he taught at the law school into his 80s.
His highly influential Foreign Affairs and the Constitution (1972) explored the Constitution's division of power between the president and Congress on matters pertaining to foreign affairs, a quest that took on particular urgency against the backdrop of the Vietnam War, then still in progress. ...
He returned to the subject in 1990 with Constitutionalism, Democracy and Foreign Affairs, a much more impassioned book, that warned of the dangers of an imperial presidency and insisted on the importance of human rights as a cornerstone of American foreign policy. Professor Henkin waged a multifront struggle to extend universalist ideas of human rights and the reach of the law. “He pushed back forcefully against the Roman observation that in war — and perhaps in foreign relations generally — the law is silent,” Sarah H. Cleveland, a law professor at Columbia, said in an interview with the Columbia Human Rights Law Review in 2007.
In his books, he took on such issues as compliance with international law (How Nations Behave, 1968) and the underlying principles of human rights (The Rights of Man Today, 1978). ... Professor Henkin's close ties to the United States government allowed him to serve as a go-between for human rights organizations and Congressional committees drafting rights legislation. He also filed numerous amicus briefs in Supreme Court cases including, most recently, Hamdan v. Rumsfeld, a 2006 case in which the court rejected the Bush administration’s plan to try Guantánamo Bay detainees before military commissions.
