HOW MANY COUNTRIES IN WWII

ALLIES(friends with Britain):
Following the German invasion of Poland
Poland: 1939, 1 September
United Kingdom: 1939, 3 September (included Indian Empire & Crown Colonies)
France: 1939, 3 September
Australia: 1939, 3 September
New Zealand: 1939, 3 September
Nepal: 1939, 4 September
South Africa: 1939, 6 September
Canada: 1939, 10 September

[edit] After the end of the Phony War
Norway: 1940, 9 April
Belgium: 1940, 10 May
Luxembourg: 1940, 10 May
Netherlands: 1940, 10 May
Greece: 1940, 28 October
Kingdom of Yugoslavia: 1941, 6 April
Soviet Union: 1941, 22 June
Tannu Tuva: 1941, 25 June

[edit] After the attack on Pearl Harbor
Panama: 1941, 7 December
Costa Rica: 1941, 8 December
Dominican Republic: 1941, 8 December
El Salvador: 1941, 8 December
Haiti: 1941, 8 December
Honduras: 1941, 8 December
Nicaragua: 1941, 8 December
United States of America: 1941, 8 December
Republic of China: 1941, 9 December
Guatemala: 1941, 9 December
Cuba: 1941, 9 December
Czechoslovakia (Government-in-Exile) : 1941, 16 December

[edit] After the Declaration by United Nations
Peru: 1942, 12 February
Mexico: 1942, 22 May
Brazil: 1942, 22 August
Ethiopia: 1942, 14 December
Iraq: 1943, 17 January (occupied by Allies in 1941)
Bolivia: 1943, 7 April
Iran: 1943, 9 September (occupied by Allies in 1941)
Italy: 1943, 13 October (formerly a member of the Axis)
Colombia: 1943, 26 November
Liberia: 1944, 27 January

[edit] After D-Day
Romania: 1944, 25 August (formerly a member of the Axis)
Bulgaria: 1944, 8 September (formerly a member of the Axis)
San Marino: 1944, 21 September
Albania: 1944, 26 October
Hungary: 1945, 20 January (formerly a member of the Axis)
Bahawalpur: 1945, 2 February
Ecuador: 1945, 2 February
Paraguay: 1945, 7 February
Uruguay: 1945, 15 February
Venezuela: 1945, 15 February
Turkey: 1945, 23 February
Lebanon: 1945, 27 February
Saudi Arabia: 1945 March
Finland: 1945, 4 March (formerly an Axis co-belligerent)
Argentina: 1945, 27 March
Chile: 1945, 11 April

[edit] After the bombing of Hiroshima
People's Republic of Mongolia: 1945, 9 August
Axis(FRIENDS WITH NAZI):
Nazi Germany
Japan
Italy
Hungary
Romania
Bulgaria
Yugoslavia
Croatia
Thailand
Finland
Manchukuo
Mengjiang
China (Reformed Government of the Republic of China at Nanking)
Burma (Ba Maw regime)
Philippines (Second Republic)
India (Provisional Government of Free India
Albania
Norway (Quisling regime)
Serbia (Nedić regime)
France (Vichy regime)
Spain (Franco regime)
Denmark (Protectorate Government)

以納粹德國為首的陣型有德、意、日、羅馬尼亞、匈牙利、保加利亞、芬蘭。
羅匈保芬四國都是為了抵抗蘇聯的共產勢力而德國作戰。

以英美為首的盟國陣型有美、英、蘇、中、澳洲、加拿大、如果要把一些較不起眼的對抗勢力，還有東南亞諸國、中美洲諸國、韓國、菲律賓、比荷盧三國，和法國反抗軍等。