There Were Two Sides in World War 2:
The Allies
Australia
Belgium
Brazil
Canada
China
Czechoslovakia
Denmark
Estonia
France
Greece
India
Latvia
Lithuania
Malta
The Netherlands
New Zealand
Norway
Poland
South Africa
United Kingdom
United States of America
USSR
Yugoslavia
The Axis
Germany
Italy
Japan
Slovakia (from Nov 1940)
Hungary (from Nov 1940)
Romania (from Nov 1940)
Bulgaria (from March 1941)