The vast changes that have occurred in the Soviet Union since Mikhail Gorbachev became its leader in March 1985 have unleashed a revolution in the Eastern bloc and fundamentally altered Soviet-East European relations and East-West relations. In particular, the changes that have unfolded in Eastern Europe since the fall of 1989 have important implications for Western security policy. As a result of the revolutionary political changes in Europe, foremost among them the unification of Germany, it is clear that NATO and the Warsaw Pact are altering their basic orientations and reordering priorities they have pursued for the last four decades.