How did world war 2 lead to the beginning of the cold war?

- Resulted in two super powers with opposing ideologies
- America had the atomic bomb, displayed power through the bombings of Hiroshima and Nagasaki
- USSR had suffered immensely from WWII: 25 million people killed, 1700 cities and 70,000 villages were ruined, 70% of her industries and 60% of her transportation facilities were destroyed. 
- USA experienced economic boom, it's industrial grew by 90% between 1940-44. End of the war may have meant end of economic growth
- Power vacuum in the middle of europe, due to Germany being absent. Decisions were made at Yalta and Potsdam to divide Germany into zones of occupations 1945
- Red army had liberated and controlled most of the Red army. 1944, Churchill and Stalin concluded the "Percentages Agreement" based on the influences of the Balkan states. Romania 10:20, Greece 90:10, Bulgaria 25:75, Hungary 25:75, Yugoslavia 50:50
Japan occupied Korea, China and Indochina which they had taken in through the war. In 1943, Churchill issued the Cairo Declaration, " Japan will also be expelled from all other territories which she has taken by violence and greed...KJorea shall become free and independent". This was agreed by USSR, Britain and US at Potsdam. Powr vacuum when the Japanese surreneder ---> civil war in China started again
Relations between the USSR and USA were soured when Russia signed the Nazi-Soviet Pact in 1939, enabling Hitler to start the war. Stalin wanted a second front to ease tensions on the Red Army men in 1941, it wasn't until 1944 that the Western powers finally invaded France and created a second Front in Europe. (330,000 americans died while 25-30million russians died)
The war ended with America dropping an A-bomb on Hiroshima and Nagasaki, without telling the USSR before two days before they were meant to join America to defeat Jaoan. 
"Last battle of the Second World War and the first battle of the Cold War"