World War II involved Japan.
The Axis powers ( Achsenmächte , 枢軸国 Sūjikukoku , Potenze dell ` Asse ) , also known as the Rome -- Berlin -- Tokyo Axis , were the nations that fought in World War II against the Allied Powers . World War II . Supplied by the Soviet Union , from late 1939 to early 1941 , in a series of campaigns and treaties , Germany conquered or controlled much of continental Europe , and formed the Axis alliance with Italy and Japan .