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