Answer :
There are different opinions about this but these four might answer your question. 1) There were 2 different world views - capitalism (US) and communism (Russia). 2)Both countries wanted to have military security against being attacked ever again. Russia knew the US had an atomic bomb and so they built up their weaponry. 3) Both countries tried to win over the most allies 4) Russia wanted war repatriations from Germany but the US and Britain wanted to help Germany get back on its feet with a democratic government. Another one could be about the resentment both sides held. Britain and US were resentful that Russia had signed a pact with Hitler in 1939. Russia was resentful that Britain and US had tried to stop the Russian Revolution in 1917.
Answer:
* American fear of communist attack.
* Truman's dislike of Stalin.
* USSR's fear of the American's atomic bomb.
* USSR's dislike of capitalism.
* USSR's actions in the Soviet zone of Germany.
* America's refusal to share nuclear secrets.
Explanation: I added more just in case you need more.
