Japan and an alliance without reciprocity

Japan's agreements with the Soviet Union limited what the Tripartite alliance meant in practice. A settlement of the 1939 border conflict preceded a neutrality agreement in April 1941, two months before Operation Barbarossa. Japan did not join Germany's attack on the Soviet Union from the east. Nor did the German and Italian declarations against America lead Japan to declare war on the Soviets. War between Japan and the Soviet Union resumed only when the Soviet Union eventually declared it. Accounts differ over how far Japan expected the European Axis powers to declare war on America, so the absence of reciprocity should be kept separate from assumptions about prior Japanese expectations.