George Frost Kennan (February 16, 1904 – March 17, 2005) was an American diplomat, political scientist, and historian. He was known best as an advocate of a policy of containment of Soviet expansion during the Cold War on which he later reversed himself. He lectured widely and wrote scholarly histories of the relations between USSR and the United States. He was also one of the group of foreign policy elders known as "The Wise Men".