1. 1 Unit Four World War I World War II

2. 2 Russian Revolution  Czar Nicolas has his power removed and the Communist party takes over the Soviet Union

3. 3 Treaty of Versailles  This treaty ends World War I  Punishes Germany for acts during World War I

4. 4 Depression  Economic  Sustained, long-term downturn in economic activity

5. 5 Nazism  The political party led by Adolf Hitler

6. 6 Holocaust  The removal and killing of over 6 million Jews during World War II

7. 7 Cold War  A verbal and economic war between the United States and the Soviet Union

8. 8 Superpowers  A country with a dominant position in the international system of countries

9. 9 Soviet Union  A country that existed in eastern Europe between 1922 and 1991

10. 10 Collapse  to break down; come to nothing; fail

11. 11 Reunification  to make or become a single unit again; unite