List of countries involved in World War II
Formal Participants in World War II
Axis Powers (signers of the Tripartite Treaty)
co-signers of the Tripartite Treaty
Countries that were annexed by, or at war with, Axis Powers before the World War II
Allied Powers
Supporters of the Allies
Countries that were attacked, occupied, or switched sides during the war
(Most countries below had declared their neutrality before being assaulted.)
- Albania (occupied by Italy April 7th 1939, by Germany September 26th 1943)
- Belgium (invaded by Germany May 10th 1940)
- Czechoslovakia(1) (Bohemia and Moravia occupied by Germany March 15th 1939)
- Denmark (occupied by Germany April 9th 1940, Greenland occupied by USA April 9th 1941)
- Estonia (annexed by the Soviet Union June 18th 1940, occupied by Germany September 5th 1941, re-annexed by the Soviet Union in 1944)
- Finland (attacked by the Soviet Union November 30th 1939 and June 26th 1941)
- Greece (invaded by Italy October 28th 1940, German occupation from April 6th 1941)
- Iceland (occupied by Great Britain May 10th 1940, by USA from July 1941)
- Iran
- Latvia (annexed by the Soviet Union June 18th 1940, occupied by Germany June 25th 1941, re-annexed by the Soviet Union in 1944)
- Lithuania (annexed by the Soviet Union June 18th 1940, occupied by Germany June 22nd 1941, re-annexed by the Soviet Union in 1944)
- Luxembourg (invaded by Germany May 10th 1940)
- The Netherlands (invaded by Germany May 10th 1940)
- New Guinea (invaded by Japan)
- Norway (invaded by Germany April 9th 1940)
- Philippines (invaded by Japan)
- Syria
- Thailand (Occupied by Japan, declared war on the United States and United Kingdom on January 25 1942)
- Tunisia (Used by Italian and German troops to attack Egypt. Later occupied by Allied forces)
- Yugoslavia(3) (German/Italian/Hungarian/Bulgarian occupation from April 6th 1941)
Countries that remained nominally neutral
Notes:
- Slovakia proclaims independence of Czechoslovakia on March 14th, 1939. Nazi German influence and Wehrmacht presence was considerable until the German occupation in September 1944. The rest of Czechoslovakia, the provinces Bohemia and Moravia, were occupied by Germany March 15th 1939, and proclaimed German protectorates.
- Egypt was technically neutral, but Cairo soon became a major military base for the British forces. This was because of a 1936 treaty by which Britain argued it had the right to station troops on Egyptian soil in order to protect the Suez Canal.
- Yugoslavia began the war as a neutral but Yugoslavia's Regent signed the Tripartite Treaty on March 25th, 1941, and met an anti-Nazi coup d'état when he returned on March 27th. This led to German occupation from April 6th 1941.
- France surrendered to Germany on June 22nd 1940, and the Vichy government was installed, which cooperated with the Germans. However substantial French forces continued to fight on the Allied side as Free French.
- French colonies initially fought alongside their parent country. When France surrendered most recognised the Vichy government.