“L” – that is the enigmatic name by which the State Department Legal Adviser is known throughout the U.S. Government. It is also the name of his office, which includes more than 170 Attorney-Advisers stationed in Washington, DC, and abroad. While L may be little known outside government circles, the importance of the office is considerable: virtually no foreign policy decision can be made without first receiving clearance from L, and no delegation can be sent to an international negotiation or international organization without a representative of L. Just as the Solicitor General is the government's point man for constitutional questions, the Legal Adviser is the government's principal expert in international legal affairs. And just as the Solicitor General argues cases for the government before the U.S. Supreme Court, L argues on behalf of the United States at the International Court of Justice and other international tribunals.

Through the years, numerous scholars and practitioners have grappled with the question of the role of international law in shaping foreign policy. Unfortunately, what John Chipman Gray wrote in 1927 remains true today: “On no subject of human interest, except theology, has there been so much loose writing and nebulous speculation as on International Law.” In an age in which a growing number of academicians and even high-level government officials have opined that international law “is just politics,” an understanding of the role that L and international law have played in shaping contemporary American foreign policy is more important now than ever before.