In this report, the author summarizes RAND political and military analysis of Europe in 1987 through 1991 as it was carried out in support of Air Force and other planners of the U.S. military posture on that continent. He divides the analyses into four periods: the Cold War era, the period of serious arms control negotiations, the end of the Warsaw Pact and the reunification of Germany, and the end of the Soviet Union. Analyses from the last period examined two hypothetical scenarios (a limited Soviet invasion of Poland and a Syrian/Iraqi invasion of Turkey) to suggest what military structure NATO might need. The author concludes that, due to its mobility and rapid-response capability, air power is particularly suited to an era characterized by uncertainty and rapid change and thus should be the centerpiece of U.S. and NATO military forces in Europe.