The Soviet Union was able to seize control of Eastern Europe due to the following reasons:
1. **Soviet Invasions During World War II**: One of the key factors that allowed the Soviet Union to control Eastern Europe was its military actions during World War II. As Soviet forces advanced westward during the war, they occupied territories in Eastern Europe. This military presence and control over these regions enabled the Soviet Union to exert influence and establish dominance after the war ended.
2. **Yalta Conference and Treaties with Allied Powers**: At the Yalta Conference in 1945, the Allied Powers, including the Soviet Union, made decisions regarding the post-war reorganization of Europe. Agreements were reached that gave the Soviet Union considerable influence in Eastern Europe as part of the post-war settlement. Additionally, treaties and agreements signed with the Allied Powers formalized Soviet control over certain Eastern European countries, solidifying their grip on the region.
These factors, combined with the military advancements made during World War II and the diplomatic agreements reached with the Allied Powers, provided the Soviet Union with the opportunity to seize control of Eastern Europe and establish a significant presence in the region following the end of the war.
