Law of the United States
Written while Richard Nixon was conducting the American involvement in the Vietnam War, his 1972 book "Foreign Affairs and the Constitution" described the division of responsibility between the President of the United States and the Congress in conducting foreign affairs and military action, exploring how the executive branch had achieved a great measure of control despite the fact that the Constitution grants the legislative branch the power to declare war. As the practice of foreign affairs had become more complex, he detailed how Congress had gradually acceded to the President greater control in conducting American foreign relations and showed that it had not taken adequate precautions in the way these powers were wielded by the executive. In his 1990 work "Constitutionalism, Democracy and Foreign Affairs" Henkin reiterated his concerns about the growth of the Imperial Presidency and its effect on the way the nation's foreign affairs were conducted, emphasizing that the preservation of human rights must play an important role. This and other books such as "The Rights of Man Today", "How Nations Behave", and "Age of Rights", comprised a collection of works that "The New York Times" described in his obituary as being "required reading for government officials and diplomats". He was the Chief Reporter of the influential Restatement (Third) of the Foreign Relations Law of the United States.