20. How did the Marshall Plan support the Truman Doctrine and the policy of
containment?
21. Why did the United States and the USSR fight together as allies in 1941?
22. Did the United States and the USSR ever fully trust one another? Explain.
23. Using your understanding of how the United States and the USSR became allies
and their levels of trust, what problems might emerge in the postwar period?

24. What was the purpose of the 1945 war conferences in Yalta and Potsdam? Given
your prior knowledge of war conferences and agreements, what problems might arise?