Question

what was the main cause of cold war

Answer 1

Here, this will help: http://www.shmoop.com/causes-of-cold-war/

Answer 2

The Cold War began when it became clear that the future of Europe depended on the actions of the USA and the USSR in the aftermath of the Second World War. All of the European powers had been exhausted by the war - the UK was bankrupt, France, Germany, Belgium, Poland, Hungary, Romania, Yugoslavia, Greece and Italy were all in ruins. The USSR saw this vacuum of power as the perfect opportunity to extend its influence and went back on its wartime promises to the UK and USA by forcibly installing communist governments in Eastern Europe. Traditional Soviet paranoia led to a heavy military presence in these countries and massive reparations to the USSR from countries which had been allied to Germany. This paranoia also fuelled the Soviet desire to have atomic weapons; when it became clear that both sides were willing to nuke each other over their ideological differences the Cold War was set.
Between 1945 and the 80s the conflict went through several stages. From 1945 and 1949 the Soviets were touchy - they did what they wanted in Eastern Europe but hid it from the Americans, as they did not yet have atomic weapons and didn't want to fight the Americans yet. After 1949 the Communist expansion went global as Communists won the Chinese Civil War and communist insurgency began in British-owned Malaysia. In 1950 Communist North Korea invaded capitalist South Korea and the USA and its allies interviened, while China covertly aided the North. This conflict lasted until 1953 and although a ceasefire was agreed no peace deal has ever been signed. In 1954 the French lost their colony of Indochina (Vietnam) to Communist insurgency and the country was split North and South, following the same idea as Korea. In 1956 the USSR crushed a democratic revolt in Hungary. Meanwhile in Africa the French were violently expelled from Algeria and the colonies of the British were being given independence. In 1959 Cuba had a revolution and a Communist state was established in America's back yard. The USSR and the USA came close to war when it emerged that Russian missiles were being moved to Cuba; diplomatic pressure forced the Soviets to back down in 1962. From 1964 to 1973 the USA interviened to try to stop the communist insurgency in Vietnam, which turned into a proxy war with North Vietnam. This was a failure and American troops were pulled out in 1973; South Vietnam was conquered by the North in 1975. Surrounding countries in South East Asia also fell to communism: Laos and Cambodia. The British meanwhile had crushed the communists in Malaysia and given that country its independance. Spain shook off its fascist dictatorship in 1975 and became a US ally; Portugal lost its colonies in Africa after long wars and became a democracy. In Chile, the American CIA backed a right-wing coup to overthrow a left-wing democratic government and in El Salvador the Americans helped the right-wing factions to fight in a Civil war. Meanwhile, the Soviets invaded Afghanistan to try to expand their influence in Asia but were defeated by American-backed insurgents. When Nicaraguan General Noriega grew too left-wing, he was overthrown by American troops. By the 1980s the USA and the USSR had enough nuclear weapons to destroy the whole world several times over and friendship talks were held between US president Reagan and Soviet General Secretary Gorbachev. Anti-communism took root in 1989, with most of Communist Eastern Europe revolting and attempted revolution in China. the USSR collapsed in 1991.

Answer 3

@IlincaCoada01 citation is needed. ^