Meetings between the heads of governments of major powers that discuss the relations between them. During the Cold War, summit diplomacy developed as a major means by which the U.S. and the Soviet Union tested each other and tried to reach a rapprochement, or at least understanding of each other's position, on a variety of issues. Summit meetings were dramatic and comparatively infrequent events, and the hopes and fears of the world often seemed to hang on the outcome. Since the end of the Cold War, the importance of such summit meetings has vastly decreased and now they seem merely routine matters.