Japan during World War I close of the war. The prosperity brought on by World War I did not last. Although Japan's light industry had secured a share of the world market, Japan returned to debtor-nation status soon after the end of the war. The ease of Japan’s victory, the negative impact of the Showa recession in 1926, and internal political instabilities helped contribute to the rise of Japanese militarism in the late 1920s to 1930s. Japan during World War I Japan participated in World War I from 1914 to 1918 in an alliance with Entente Powers and played an important role in securing the
Declarations of war during World War I 1907 (or Hague II). For the diplomatic maneuvering behind these events, which led to hostilities between nations during World War I, see the article entitled Diplomatic history of World War I. Below is a table showing the "Outbreaks of Wars between Nations" which occurred during World War I. Indicated are the dates (during the immediate build-up to, or during the course of, World War I), from which a "de facto" state of war existed between nations. The table shows both the "Initiator Nation(s)" and the nation at which the aggression was aimed, or "Targeted Nation(s)". Events listed include those in