The United States Army Air Forces became an independent service, the United States Air Force, in 1947-the second year, supposedly, of "peace." In reality there had just begun a long conflict between the United States and its allies and the Soviet Union and the satellite states subject to it. In 1949 the United States and most of the non-Communist countries of Europe signed the North Atlantic Treaty. The United States Air Force, which had been only a token presence on the continent since the end of World War II, once more crossed the Atlantic in strength. The commitment of that service to peace and security in Europe, which continues still, has been the longest of its history. This pamphlet attempts to give the general reader some sense of the role the USAF has played in Europe since the end of World War II. It contains three sections. The first reviews the reasons for the origins of the Cold War and describes the strategic concerns that drove the United States to commit itself to the military defense of distant lands. The second section reviews the higher strategy of the North Atlantic Treaty Organization (NATO) with special reference to the central role of air power. The final section reviews the history of the United States Air Forces in Europe (USAFE) in order to show the many ways in which the United States Air Force has served American national security policy on the continent. This section is closely based on a brief history of USAFE prepared by Dr. Daniel Harrington of USAFE' s history office. I am grateful to Dr. Harrington for having made his study available to me.