Question

Use the quotation and your knowledge of social studies to answer the following question. “As the free world grows stronger, more united, more attractive to men on both sides of the Iron Curtain—and as the Soviet hopes for easy expansion are blocked—then there will have to come a time of change in the Soviet world. Nobody can say for sure when that is going to be, or exactly how it will come about, whether by revolution, or trouble in the satellite states, or by a change inside the Kremlin.” —Harry S. Truman’s Farewell Address. Why did President Truman believe that political change would come to the Soviet Union?

Answer 1

Henry Truman believed that the strength and attractiveness of the liberal world order would prevent further expansion by the Soviet Union. He thought that, as more countries became democracies and became stronger and wealthier through capitalism, there would be fewer countries for the Soviet Union to adsorb into the Communist Bloc.
Not only would there be fewer countries available for Soviet absorption, but existing Soviet satellite countries would see the free countries' success and juxtapose it with the poverty and lack of freedom in their own country. As a result, some change from the Soviet system would necessarily have to happen, eventually leading to these countries also joining the liberal world order. 

Answer 2

the answer is : the appeal of freedom and the containment of communism,