George Frost Kennan was born in Milwaukee, Wisconsin on 16 February 1904. After graduating from Princeton University in 1925 he entered the U.S. Foreign Service, and continued his education by embarking on a course of graduate study at the University of Berlin's Oriental Institute (1928-30). By the mid-30s Kennan was among a core of professionally trained specialists at the newly opened U.S. embassy in Moscow. Following World War II Kennan returned to the Soviet Union, as deputy chief of the U.S. mission in Moscow. On 22 February 1946 he sent his famous long telegram to Secretary of State James Byrnes, outlining a new, and ultimately influential, diplomatic policy of "containment" of the Soviet Union. After being recalled to Washington Kennan published "The Sources of Soviet Conduct" (Foreign Affairs, July 1947), advocating ". . . a long-term, patient, but firm and vigilant containment of Russian expansive tendencies . . . ." Though Kennan would come to disagree with the American implementation of containment, especially in its military aspects, there is little doubt that his ideas were a foundation stone of U.S. cold war policy. Kennan reached the height of his political influence under George C. Marshall in 1947-48; as head of the State Department's Policy Planning Staff he was an architect of the Marshall Plan, which directed economic aid to Western Europe and Japan as a bulwark against communist infiltration and influence. Under new Secretary of State Dean Acheson the Soviet Union was increasingly regarded as an overt military threat to the West, and Kennan lost influence. He did serve briefly as U.S. ambassador to the Soviet Union (May-September 1952), and as ambassador to Yugoslavia under Kennedy (1961-63), but he increasingly abandoned government service for academe. In 1956 he joined the faculty of the Institute for Advanced Studies' School of Historical Studies, at Princeton. During his long tenure there he published more than 15 books and numerous articles, on diplomacy, diplomatic history, and international relations; he also wrote several volumes of memoirs. Through his writings Kennan emerged as an important realist critic of idealist (or Wilsonian) American foreign policy. Kennan died at his home at Princeton on 17 March 2005, at the age of 101.

John Lukacs (János Albert Lukács) was born in Budapest on 31 January 1924, the son of a Roman Catholic father and Jewish mother. He survived the German occupation of Hungary (1944-45) but left the country for the United States with the installation of the communist regime. From 1947 to 1994 Lukacs was professor of history at Chestnut Hill College in Philadelphia. He is the author of numerous works of history, most notably on Churchill, Hitler, Stalin, and World War II in Europe, as well as several works of historical philosophy. He also published on the Cold War, including three works inspired by his friendship with George Kennan: George Kennan: A Study of Character (Yale University Press, 2007); George F. Kennan and the Origins of Containment 1944-1946 (University of Missouri Press, 1997); and Through the History of the Cold War: The Correspondence of George F. Kennan and John Lukacs (University of Pennsylvania Press, 2010). The first of these books is a biographical study of Kennan, which does not reference Kennan and Lukacs's extensive personal correspondence. The second publishes six letters discussing Kennan's idea of containment, written between Kennan and Lukacs from 20 December 1994 to 28 April 1995. The third is a published edition, edited by Lukacs, of some of the 360-odd letters written between the two men from 1952 to 2004.