After the End of World War I, Germany was left politically and economically devastated, as it lost significant portions of territory to its neighbors and it was forced to pay debts as a result of the war with the signing of the Treaty of Versailles on June 28, 1919.
On the other hand, Japan was an ally of the Entente and fought against the Imperial Geman Navy in the Pacific and Indian Oceans. After the war, Japan earned a seat in peace negotiations from which it would end up benefiting from. Militarily, the budget assigned to its navy nearly doubled, giving Japan a powerful military presence in the Pacific Ocean. A condition that favored country during the Second World War, as it gained control of much of Southeast Asia.