The Cold War started because of United States and Soviet Unions difference in view when it comes to Communism. US became more and more concerned with how the Soviet Union are showing their "expansive tendencies" when it comes to their dealings with Europe. The long telegram that was sent to the Department of State became the greatest foundation of the America's Cold War Policy of containment.
The Soviet Unions aggressive speeches and actions against Iran and Turkey gave way to the Truman's administration to show a stronger stance instead of a diplomatic approach that the previous administrations were doing. These factors guaranteed acceptance of Kennan's analysis that was expressed on the telegram.
The United States and the Soviet Union had very different ideologies and views of security. The Soviet Union wanted buffer states to protect its borders and hoped to spread communism to other countries to assist in that aim. The United States wanted to protect and defend democracy and, according to the Truman Doctrine, adopted a policy of containment. Both countries mistrusted each other, and each suspected that the other was trying to take over the world. This affected their relations with each other and their relationships with other nations.
