In more than one way, the Cold War began even before the World War II ended in 1945. The roots of the conflict between the Soviet Union and the United States developed after the Russian Revolution of 1917, but most historians consider the beginning after the fall of Nazi Germany, since that is the period when relations between Moscow and Washington began deteriorating.
The events of the decades-long struggle took place all over the world, in a fight for global supremacy. I'm sure you've all seen a movie or two regarding these events. The capitalist United States and the communist Soviet Union made a necessary alliance against Adolf Hitler, which resulted in a successful war campaign. However, after the battles old suspicions and mistrust resurfaced making competing ideologies of the postwar society bitter enemies.
Through time presidents changed in offices, yet the conflict remained for over forty years. The term "Cold War" was first used in 1947 by Bernard Baruch, a senior advisor to President Harry Truman, to describe an ongoing situation in which sides were afraid of fighting each other directly.
The struggle for political control
With both superpowers possessing nuclear weapons, there was a real chance they might destroy the world. Therefore they fought each other indirectly, using words as weapons, threats to make the other side look weaker, creating havoc through conflicts in different parts of the world. The actual conflict began with the struggle for political control. During the last few months of World War II, Soviet military occupied all of Central and Eastern Europe. Using military forces to empower the Communist parties in Eastern Europe caused the crush of democracy on the continent. Slowly but surely, communism spread from one nation to another.
By 1948, pro-Soviet regimes were in power in Poland, Bulgaria, Hungary, Romania, and Czechoslovakia. At one point there was a significant possibility that the communist parties would be elected in both France and Italy. Taking into consideration the Soviet influence in Eastern Europe, the United States and Britain were determined to stop the communism from spreading in Western Europe. The Soviet Union power was growing and soon they sought to expand the security zone further into North Korea, Central Asia and the Middle East.
The United States established a security zone of its own in Western Europe, Latin America, Southeast Asia, Australia, New Zealand and Japan. Between 1945 and 1948 the conflict was more political than military. Both superpowers argued at the United Nations, meanwhile seeking additional allies who shared their visions of a postwar world.
By 1950s certain events made the Cold War an increasingly militarized struggle. Tensions over occupied Germany, the pronouncement of the Truman Doctrine, the outbreak of the Korean War and the establishment of the North Atlantic Treaty Organization (NATO) were the main issues for the Soviet Union. United States, on the other hand, had problems with the communist takeover in China, the Soviet nuclear weapon program and the formulation of the Warsaw Pact. United States foreign policy accordingly sought to contain the Soviet Union from further expansion, which has stayed active through a variety of incarnations from 1952 until the demise of the Soviet Union in 1991.