Final answer:
The Soviets promised to allow free elections in Eastern Europe during the Yalta Conference, but later broke this commitment, causing tension in the post-war period.
Step-by-step explanation:
The Soviets made a commitment during the Yalta Conference to allow free elections in Eastern Europe. However, they later broke this commitment, causing tremendous tension in the post-war period. Despite the agreement, Communist governments backed by the Soviet Red Army were established in several Eastern European countries, such as Hungary, Poland, Romania, Bulgaria, and East Germany.