<Tr> <Th> Timeline Conflicts Historiography </Th> </Tr> <Tr> <Th> Cold War II </Th> </Tr> <P> The Origins of the Cold War involved the breakdown of relations between the Soviet Union versus the United States, Great Britain and their allies in the years 1945--1949 . From the American - British perspective, first came diplomatic confrontations stretching back decades, followed by the issue of political boundaries in Central Europe and political non-democratic control of the East by the Soviet Army . Then came economic issues (especially the Marshall Plan) and then the first major military confrontation, with a threat of a hot war, in the Berlin Blockade of 1948--1949 . By 1949, the lines were sharply drawn and the Cold War was largely in place in Europe . Outside Europe, the starting points vary in the late 1940s or early 1950s . </P> <P> Events preceding the World War II and even the Russian Revolution of 1917, underlay older tensions between the Soviet Union, European countries and the United States . A series of events during and after World War II exacerbated tensions, including the Soviet - German pact in 1939, the Anglo - Americans repeated postponement of an amphibious invasion of German - occupied Europe, the Western allies' support of the Atlantic Charter, Soviet rejection of decisions about Eastern European democracy made in wartime conferences and the Kremlin's control of an Eastern Bloc of Soviet satellite states . </P>

When did the cold war alignment of britain and the united states versus the soviet union begin