* American fear of communist attack

* Truman’s dislike of Stalin

* Russia’s fear of the American's atomic bomb

* Russia’s dislike of capitalism

* Russia’s actions in the Soviet zone of Germany

* America’s refusal to share nuclear secrets

* Russia’s expansion west into Eastern Europe + broken election promises

* Russia’s fear of American attack

* Russia’s need for a secure western border

* Russia’s aim of spreading world communism

This feeling of suspicion lead to mutual distrust and this did a great deal to deepen the Cold War