To the amazement of the major powers, Japan had soundly defeated the Russian imperial forces in the Russo-Japanese War (1905) and emerged as the only industrialized society in the Far East. Despite this enhancement of prestige and prosperity, the Japanese faced several nagging problems:
Lack of Respect. Japan's victory over Russia had failed to wrest the ardently desired reparations payments. Theodore Roosevelt, the chief peace negotiator at the end of the war, had opposed the imposition of a heavy financial burden on reeling Russia. The Japanese were counting on Russian payments as a means to reduce a huge debt incurred during the conflict.
Further, Japanese sensibilities had been rubbed raw by a series of insults from the United States, where, among other things, Asians in California were segregated in public schools and prohibited from owning land.
In the eyes of many Japanese, the war had foisted upon their nation a staggering financial obligation and little international respect.
Lack of Raw Materials. Japan was an emerging industrial power in the early 20th century, but lacked sufficient domestic supplies of iron and coal to sustain its desired development.
Lack of Food. As the Japanese population expanded in the early 1900s, it became clear that the nation's limited supply of arable land was incapable of supplying sufficient food.
Lack of Land. Japan, a nation of islands, believed that it was approaching its maximum density and continued to cast hungry glances at the Asian mainland as a potential target of expansion.
The major powers of Europe were reluctant to allow Japan to share in their exploitation of China, but the triumph over Russia brought Japan primacy in Korea and increased influence in southern Manchuria. In Korea, the Japanese forced the abdication of the king and installed their own governor. The latter's assassination in 1909 led to the formal annexation of Korea the following year. In China, the Japanese reluctantly paid lip service to the Open Door Policy, but longed to increase their influence at the expense of the resident European imperial powers or the Chinese themselves.
When war erupted in Europe in August 1914, Japan promptly sided with the Allies and issued a declaration of war on Germany. Japanese activity during the conflict was noteworthy in three respects:
The Occupation of German Possessions. Japan took advantage of the major belligerents' preoccupation with the war in Europe to seize German holdings on the Shantung (Shandong) Peninsula of China. They also took possession of the Kaiser's western Pacific islands — the Marianas, Carolines and Marshalls.
China made a feeble attempt to use wartime confusion as a means to regain control over some of its occupied lands, but a bellicose Japanese government issued its far-reaching Twenty-One Demands to squelch any Chinese resurgence.
The Japanese had a strong postwar case justifying their hold on German Pacific possessions. Foremost, they enjoyed actual physical possession and they also had concluded a secret agreement with Britain that essentially divided German island holdings between the two powers at the equator; Britain was to take islands to the south and Japan those to the north.
In Paris, such agreements ran counter to Woodrow Wilson’s principle of national self-determination. In the end, however, the American president compromised, allowing Japan to maintain economic rights on the Shantung Peninsula, subject to the later return of the area to Chinese control. The North Pacific German island holdings were granted to Japan under the newly created mandate system.
Development of Heavy Industry. The insatiable demands of the Allies for war matériel and other industrial goods created a tremendous industrial boom in Japan. The resulting trade was extremely valuable to the Allies and highly profitable for Japan.
Siberian Intervention. Following the Bolshevik Revolution (1917) and the Russian conclusion of a separate peace with Germany (1918), the Allied powers dispatched an expeditionary force to Siberia. The primary aims of this venture were to retrieve war matériel that was now available to both the Bolsheviks and the Germans, and give support to anti-communist Russian forces fighting for control of the country.
The overwhelming size of the Japanese force and its leaders' reluctance to withdraw from Russia further alienated the other Allied nations.
Japan's Legacy from World War I
Many Japanese regarded their country's participation in the war as a great success. All sectors of the economy boomed as Japanese industry responded to the demands of the Allied war machines. Increasingly, too, Japanese products found their way into other Asian markets left untended by the warring European powers. This economic euphoria was tempered somewhat at home by increasing labor-management strife and the emergence of a vocal leftist political movement.
Elsewhere, Japan was viewed with either suspicion or hatred. The Koreans and Chinese deeply resented Japanese incursions; these resentments would fester through the 1920s. Other Allied governments protested Japanese opportunism during the war, but to no avail. In spite of their misgivings, the Allies recognized Japan as a great power and made that nation a full partner in the negotiations at Paris in 1919. Japan was rewarded with mandates over the islands seized during the war, but it failed to gain a highly desired statement on racial equality in the Covenant of the League of Nations. Britain opposed the latter statement, largely because of its fear that it would incite equality or independence movements within its own vast empire. Wilson was fairly sympathetic to the Japanese request, but gave in to British pressure; the United States abstained on the vote on racial equality — the equivalent of a vote against. This action was tucked away by the Japanese in their growing list of real or imagined slights.
Japan joined the League of Nations in 1920 and served as a permanent member of the Council. In 1922, the Japanese participated in the Washington Conference, an international effort to slow the naval arms race.
See World War I Time Table and Wilson's Search for Peace.