Towards the end of the Second World War, the USA, Britain and France (capitalist countries) disagreed with the USSR over what to do with the countries devastated by war
Britain and the USA felt that European nations - including Germany - should be helped to recover quickly and so return to a time of peace when they cooperated and traded freely with each other
The USA was willing to pay huge amounts of money - through the Marshall Plan - to help this recovery
But Stalin (leader of the USSR) wanted to keep Germany weak because Germany had invaded the USSR during the war, and he wanted to keep Soviet troops inside the eastern European countries he had invaded during the war
The USSR claimed Finland, Lithuania, Estonia and Latvia, and gained land from Czechoslovakia and Romania
The USSR now either controlled these places directly, or governments under Stalin's influence ruled them; Soviet territory had expanded nearly 500 kilometres westwards and gained control of over 20 million more people
Soon, helped by Stalin, communists took over in Bulgaria, Hungary and Poland
Even Germany was divided in two, with Soviet troops controlling the eastern part of Germany, while French, British and American troops controlled the western part