Emerging Chinese nationalism, the victory of the communists in Russia, and the growing presence of the United States in East Asia all worked against Japan's postwar foreign policy interests. The four-year Siberian expedition and activities in China, combined with big domestic spending programs, had depleted Japan's wartime earnings. Only through more competitive business practices, supported by further economic development and industrial modernization, all accommodated by the growth of the zaibatsu (wealth groups--see Glossary), could Japan hope to become predominant in Asia. The United States, long a source of many imported goods and loans needed for development, was seen as becoming a major impediment to this goal because of its policies of containing Japanese imperialism.

An international turning point in military diplomacy was the Washington Conference of 1921-22, which produced a series of agreements that effected a new order in the Pacific region. Japan's economic problems made a naval buildup nearly impossible and, realizing the need to compete with the United States on an economic rather than a military basis, rapprochement became inevitable. Japan adopted a more neutral attitude toward the civil war in China, dropped efforts to expand its hegemony into China proper, and joined the United States, Britain, and France in encouraging Chinese self-development.

In the Four Power Treaty on Insular Possessions (December 13, 1921), Japan, the United States, Britain, and France agreed to recognize the status quo in the Pacific, and Japan and Britain agreed to terminate formally their Treaty of Alliance. The Five Power Naval Disarmament Treaty (February 6, 1922) established an international capital ship ratio (5, 5, 3, 1.75, and 1.75, respectively, for the United States, Britain, Japan, France, and Italy) and limited the size and armaments of capital ships already built or under construction. In a move that gave the Japanese Imperial Navy greater freedom in the Pacific, Washington and London agreed not to build any new military bases between Singapore and Hawaii.

The goal of the Nine Power Treaty (February 6, 1922), signed by Belgium, China, the Netherlands, and Portugal, along with the original five powers, was the prevention of war in the Pacific. The signatories agreed to respect China's independence and integrity, not to interfere in Chinese attempts to establish a stable government, to refrain from seeking special privileges in China or threatening the positions of other nations there, to support a policy of equal opportunity for commerce and industry of all nations in China, and to reexamine extraterritoriality and tariff autonomy policies. Japan also agreed to withdraw its troops from Shandong, relinquishing all but purely economic rights there, and to evacuate its troops from Siberia.

In 1928 Japan joined fourteen other nations in signing the Kellogg-Briand Pact, which denounced "recourse to war for the solution of international controversies." Thus, when Japan invaded Manchuria only three years later, its pretext was the defense of its nationals and economic interests there. The London Naval Conference in 1930 came at a time of economic recession in Japan, and the Japanese government was amenable to further, cost-saving naval reductions. Although Prime Minister Hamaguchi Osachi had civilian support, he bypassed the Naval General Staff and approved the signing of the London Naval Treaty. Hamaguchi's success was pyrrhic: ultranationalists called the treaty a national surrender, and navy and army officials girded themselves for defense of their budgets. Hamaguchi himself died from wounds suffered in an assassination attempt in November 1930, and the treaty, with its complex formula for ship tonnage and numbers aimed at restricting the naval arms race, had loopholes that made it ineffective by 1938.

Data as of January 1994