Hello There!
Your answer would be "<u>because he believed that the Soviet Union wouldn't risk war by expanding communism</u>"
Your key word in the question would be containment. Containment means to keep something that is harmful under control. George made this a policy towards the Soviet Union. The reason why he believed that containment was the best response to the expansion is because the Soviets were trying to expand their communism through out Europe, but the United States didn't want to let that happen, so they controlled the expansion of the Soviet union that is spreading throughout Europe, so other countries do not get influenced by communism. This policy was known for being used in the Cold War. Communism was dangerous during their time. If an economy lacks the amount of strength to be a strong economy, then they would easily take communism into their economy, since it is the only option for them to keep their economy functioning.
George F. Kennan's goal was to make sure that the economies in Europe were strong enough to stand up for themselves, without having other countries help them stay strong. Communism would destroy economies and make them weaker, to the point where they would need to depend on another country to help them (Soviet Union).
Since the Soviets did not want to get into war with the United States, they stopped expanding their communism through out Europe. If they did not stop expanding their communism through out Europe, then they would've went to a brutal war with the U.S.
