tensions in cold war

The first atomic bomb was used by the United States against Japan at the end of World War Two. in four years, the Soviet Union also developed the atom bomb. America's fears were increased by the fact that the Soviet Union was actively expanding its military influence in Eastern Europe at the time. So the United States adopted a policy for keeping the soviet union at bay. Related to this policy was the strategy of deterrence, which sought to protect the Western nations from the possibilty of nuclear attack by the Soviet Union. The concepts of containment and deterrence were to have a strong influence on Soviet-American relations over the following decades. In order to protect its interests in the region, the United States joined with several Western European nations in 1949 to form the North Atlantic Treaty Organization (NATO). In 1955, the Soviet Union formed a similar alliance among the Eastern European nations known as the Warsaw Treaty Organization. The international tensions that arose between these two superpower blocs became known as the "Cold War."