According to George Kennan how will United States slow Russia's expansive tendencies

Kennan argued that America's primary goal should be to prevent the spread of communism to non-communist nations; that is to say, "contain" communism within its borders. The Truman doctrine aimed at this goal and containment was one of its key principles. A corollary of the contention was the domino effect theory, according to which allowing a regional state to initiate a revolutionary process toward socialism would threaten that entire region.

i dont know sorry, but ik that you need to pay attention in class

first paragraph (and busy all the night ,with a silence deep and white )