It is hard to decide when the Cold War ended unless we can determine when it began. Did it begin after World War II, when the two most powerful countries to emerge from that conflict confronted each other in what seemed a geopolitical zero-sum game? Or did it begin earlier, with the victory of the Bolsheviks in Russia in 1917, in which case the rivalry following World War II was merely a new manifestation of an existing ideological struggle?

If the Cold War began in 1945 or 1946, then it must have ended in 1990, when the iron curtain across Europe was dismantled and there was no longer an East-West military confrontation. By the fall of that year, the Central and Eastern European countries that had been under Soviet dominance since the end of World War II were allowed to choose noncommunist governments, Soviet forces were withdrawn from the area, and Germany was unified with Soviet blessings. Soviet President Mikhail Gorbachev even signed an agreement that permitted the newly united Germany to remain in the North Atlantic Treaty Organization (NATO), the alliance that had been created to prevent the Soviet conquest of Western Europe. Furthermore, the Soviet government agreed to reduce its conventional forces in Europe to levels comparable to those in the NATO countries. Military competition outside Europe also essentially ended in 1990 when the Soviet Union voted with the United States and its NATO allies to resist Iraq�s aggression against Kuwait.

If the Cold War really began in 1917, however, the end might have come at a different time. If the conflict was basically ideological rather than geopolitical, it would have ended when one side or the other abandoned the ideology that had caused the conflict in the first place. Subsequent events, such as the attenuation of military confrontation and the resolution of geopolitical disputes, would have been important not because they marked the end of the ideological struggle but because they confirmed its end.

Some of the first histories of the Cold War, written while it was still at its height, described it as beginning in 1917. D.J. Fleming, a professor at Vanderbilt University, published a two-volume study in 1961 entitled The Cold War and Its Origins: 1917-1960, that traced the origins of the Cold War to the Bolshevik Revolution. A similar conclusion was reached by the French scholar and journalist Andr� Fontaine four years later, in his book La Guerre Froide (subsequently published in English under the title History of the Cold War). These authors differed in their opinions about which side was responsible. Fleming considered the United States primarily responsible because, in his view, it tried to combat communism by military force rather than peaceful means. For Fontaine, in contrast, it was a clash between Woodrow Wilson�s espousal of peace based on political liberty and the Bolshevik leaders� conviction that the proletarian revolution would either sweep Europe or be destroyed by the European powers. For example, Fontaine contrasts Wilson�s message to Congress of April 2, 1917, when he stated that �peace must be planted on the tested foundations of political liberty,� with Leon Trotsky�s statement to the Congress of Soviets later the same year: �Either the Russian Revolution will create a revolutionary movement in Europe, or the European powers will destroy the Russian Revolution.�

Although the Bolsheviks subsequently replaced Trotsky�s theory of permanent revolution with Josef Stalin�s �socialism in one country,� the idea that a �proletarian dictatorship� would eventually sweep the world persisted. Until it did, the Soviet Union would be the bastion of proletarian interests and the protector of �socialist� revolutionaries wherever they might emerge.

Though they were often preoccupied with other concerns, Soviet leaders from Lenin to Chernenko never deviated from an ultimate belief in the eventual victory of their version of socialism throughout the world. This did not mean that they refused to make common cause with class enemies whenever they felt weak. Dividing the �bourgeois� or �imperialist� camp was a consistent Soviet goal for decades. This strategy explains the rapprochement with a defeated Germany at Rapallo in 1922, the attempt to create a �united front� against fascism in the 1930s, the sudden alliance with Hitler in 1939, and the limited cooperation with countries at war with Germany and Japan following the German invasion of the Soviet Union in 1941.

The Soviet Union emerged from World War II as what seemed to most observers the second most powerful state in the world. Nuclear weapons, however, made a general East-West conflict unthinkable. Soviet leaders adopted a policy of �peaceful coexistence,� which some outsiders interpreted as a renunciation of the international class struggle that Marx and Lenin had predicted would eventually bring about a dictatorship of the proletariat everywhere.

That interpretation, however, was not correct. Soviet political dictionaries defined �peaceful coexistence� as the appropriate form of �the international class struggle� in a world with nuclear weapons. The class struggle would continue, but without resort to all-out war, which would be suicidal. Soviet leaders, of course, did not go out of their way to stress this aspect of �peaceful coexistence� when they were trying to wring concessions from their Western counterparts, but they made sure that their people at home got the message. After US President Richard Nixon and Soviet General-Secretary Leonid Brezhnev proclaimed the onset of �d�tente� in 1972, Soviet propagandists frequently reminded Soviet citizens that there could be no d�tente in the realm of ideology. The international class struggle proceeded, and when �national-liberation� struggles against �imperialism� broke out, it was considered a Soviet duty to support them in any feasible way so long as that support did not bring the Soviet Union into direct conflict with the United States.

Furthermore, �peaceful coexistence,� limited as it was, was not applied generally, but, instead, applied only to relations between countries �of different social systems.� In other words, it was permissible for a �socialist� country to use military force to preserve the �gains of socialism� in another country, even if it was determined to avoid war with the United States or NATO. This was the rationale for the Soviet military intervention in Hungary in 1956, in Czechoslovakia in 1968, and in Afghanistan in 1979.