2. The Players

3. The Allied Power
Great Britain
France
Russia
Italy
United States

4. The Allied Power
Italy initially had a treaty with Germany, but recanted and secretly allied with the Allied Powers. The United States joined the Allied Powers in 1917 after the country could no longer stay neutral, as Woodrow Wilson had planned in the Proclamation of Neutrality and other reasons involving kinship and propaganda. The Allies were ultimately comprised of 25 nations.

5. The Central Power German Empire the Austro-Hungarian Empire
and later the Ottoman Empire (Turkey)

6. The Central Power
These nations banded together, mostly out of national pride, and for revenge for previous losses (i.e the Bulgarians to the Serbs in 1913). These alliances were sloppy: some of the nations were not aligned with others at all times, or declarations of war were not made against all the Allied Powers.

7. Four Main Causes for WWI
Nationalism
Imperialism
Militarism
Lack of International Organization

8. World War II

9. The Players

10. The Allied Powers United Kingdom (England, Great Britain)
United States (America, USA)
Soviet Union (USSR, Russia)
France
Canada
Australia
China

11. The Axis Power
Germany
Japan
Italy
Hungary
Romania
Bulgaria
Yugoslavia

12. The Axis Powers
The alliance began to form in First, on October 15, 1936 Germany and Italy signed a friendship treaty that formed the Rome-German Axis. It was after this treaty that Italian dictator Benito Mussolini used the term Axis to refer to their alliance. Shortly after this, on November 25, 1936, Japan and Germany both signed the Anti-Comintern Pact, which was a treaty against communism.
An even stronger alliance was signed between Germany and Italy on May 22, 1939 called the Pact of Steel. This treaty would later be called the Tripartite Pact when Japan signed it on September 27, Now the three main Axis Powers were allies in the war.