

Japan’s deployments helped to relieve strain on the British Navy and eventually on the U.S. Its navy protected allied shipping in the Pacific and Indian Oceans from German commerce raiders, and escorted British Dominion (Australian, New Zealand, and Indian) and French troops from Asia to the Middle East. In addition, Japan defended merchant ships and troop transports. Japanese industry constructed merchant shipping for Britain and was in the process of building additional merchant ships for the United States as the war ended. 8 In 1914, Japan notably returned three cruisers to Russia it had captured nine years earlier in the Russo-Japanese War. It sold arms and munitions to Britain and Russia and built 12 destroyers for France, resulting in a boost to the Japanese economy as exports increased by 400 percent. Japan provided its allies with materials as well as warships and merchant ships. 6 British forces eventually defeated the German warships following engagements in the East Pacific near Chile and off the Falkland Islands. Japanese naval forces hunted German cruisers, driving them east, away from critical sea lines of communication in the Indian and western Pacific Oceans. In May 1915, China agreed to most of the provisions except for the secret terms.īeyond its focus in East Asia, Japan also provided significant support to the Allies’ overall efforts. After China leaked the terms, Britain and United States objected, resulting in a humiliating diplomatic setback for Japan and distrust within the alliance in the early stages of the war. The demands contained a set of secret provisions that allowed Japanese control of China’s police and prohibited China from granting additional concessions to other foreign powers.

Launching of Japanese Destroyer Katsura, 4 March 1915 (NHHC)įollowing its territorial conquests, Japan issued its infamous “Twenty-One Demands” to China in early 1915 to secure additional privileges, such as rights to Shantung Province and extending Japan’s lease over Port Arthur in Manchuria. 5 In addition, Japan conquered German possessions in Oceania: the Caroline, Marianas, Marshall and Yap islands. Marking a change in the character of war, the battle featured the first ever use of Japanese seaplanes, launched from an air carrier, to sink a German minelayer and bombard the German positions. Japan led a joint Anglo-Japanese military operation, consisting of about 25,000 troops, to defeat the German forces in Tsingtao, which surrendered in November 1914. Japan’s contributions during the war initially focused on seizing German territory in the Far East. Japanese leaders considered the opportunity that the war presented as “one chance in one thousand” to increase its territory while German forces were concentrated in Europe. Japan leveraged the war as an opportunity to honor its alliance with Great Britain, act as a great power, and promote its expansionist policies. From a Japanese perspective, Germany’s victory in the war could lead to increased competition in East Asia. Germany kept its Far Eastern squadron and garrisoned 3,500 troops and 2,500 reservists in Tsingtao. At the outbreak of the Great War, Germany controlled the port of Tsingtao, located on the Shantung Peninsula in eastern China. Japan’s leadership recognized the unfolding conflict in Europe presented both a threat against and an opportunity to advance Japan’s interests. Germany ignored the warning, prompting Japan’s declaration of war on 23 August, followed by a second declaration of war against Austria-Hungary on 25 August. On 14 August, Japan issued an ultimatum to Germany to remove its forces and surrender its territory in China and island possessions in the Pacific. 3 When Great Britain declared war against Germany on 2 August 1914, Japan mobilized its navy, of about 100 warships. Japan and Britain signed a treaty in 1902 to defend against the threat of Russian expansion in Asia and in light of Britain’s decreasing monopoly of control of the seas. Japan entered the conflict to support its ally, the Great Britain. 2 In balance, Japan made a strategic decision to advance its interests and provided important contributions to the Allied victory. However, Japan deployed its navy to its limit, and earned gains from the war commensurate with its contributions. 1 Westerns have critiqued Japan’s participation in World War I as opportunism. The war resulted in Japan’s acquisition of territory, economic boom, and emergence as a great power with a primary seat at the table during the signing of the Treaty of Versailles in June 1919. Although Japan suffered about 2,000 casualties in the war, fighting took place outside of the country, which remained largely unscathed.
