Militaries

World War II was fought between two opposing military alliances, the Allies and the Axis.

Axis

1. Germany (Enters WWII in 1939)
2. Japan (Enters WWII in July 27, 1937 When Japan invades China. This starts a chain of events that will lead to Pearl Harbor (U.S. Enters War, December 8, 1941, one day after the December 7, 1941 attack on Pearl Harbor)
3. Italy (Enters WWII June 10, 1940 (Fall Of France))
4. Bulgaria (Enters WWII on March 1, 1941 and switches sides on September 9, 1943)
5. Hungary (Enters WWII in 1941 and is captured in 1944)
6. Romania (Enters WWII in 1941 and switches sides in 1944)
7. Finland (Enters WWII in 1939 during the Winter War and later the Continuation War in 1941.)
8. Slovakia (Enters WWII in 1939 when it is annexed to Germany and is later captured in 1945)

Allies

1. China (Enters WWII on July 27, 1937)
2. Poland (Enters WWII on September 1, 1939)
3. Great Britain Including the Commonwealth Armies of Australia, British India, and New Zealand (Enters WWII on September 3, 1939)
4. France (Enters WWII on September 3, 1939) (France was taken out of the war early (June 22, 1940) by Germany's blitz war tactics. Despite being under German control for the majority of the war (1939 - 1944), France developed an underground Resistance that can't be overlooked in the success of the Allied landings In Normandy on June 6, 1944)
5. South Africa (Enters WWII on September 6, 1939)
6. Canada (Enters WWII on September 10, 1939)
7. Denmark (Enters WWII on April 9, 1940)
8. Norway (Enters WWII on April 9, 1940)
9. Belgium (Enters WWII on 
10. Netherlands (Enters WWII on 
11. Luxembourg (Enters WWII on 
12. Greece (Enters WWII on October 28, 1940 after Invaded by Axis)
13. Yugoslavia (Enters WWII on April 6, 1941 after invaded by Axis)
14. Soviet Union (Enters WWII on June 22, 1941, German Invades Second Front: 'Operation Barbarossa')
15. United States, Philippines, and Caribbean nations (Enter WWII on December 8, 1941 after the December 7 attack on Pearl Harbor, Hawaii)
16. Czechoslovakia (Enters WWII on December 16, 1941)
17. Mexico (Enters WWII on May 22, 1942)
18. Brazil (Enters WWII on August 22, 1942)

Military Units

Below is the directory for all of the military units operated by the above countries during World War II.

Germany

• List of Luftwaffe Units
• List of Heer Units
• List of Kriegsmarine Units

United States

• List of US Army Air Forces Units
• List of US Army Units
• List of US Navy Units
• List of US Marine Corps Units

Japan

• List of IJA Units
• List of IJAAF Units
• List of IJNAF Units
• List of IJN Units

Soviet Union

• List of Red Army Units
• List of VVS Units
• List of Red Navy Units

Italy

• List of Royal Italian Army Units
• List of Regia Aeronautica Units