Basic Character

The Washington Conference was held from 12 November 1921 to 6 February 1922 in the United States’ capital. Under the auspices of that country, nine nations joined the conference: Belgium, Britain, China, France, Italy, Japan, the Netherlands, and Portugal. The nine powers had two things generally in common. First, these countries had been victorious in the First World War, apart from the Netherlands, which had remained neutral. Second, all these countries (except China itself) enjoyed various privileges in China. China’s participation was both necessary and important, as one of the main purposes of the conference was to take the initial steps toward China’ equal status in the international community. This was an attempt to remove the major cause of conflicts in the region, particularly due to the rivalry between European powers and Japan in exploiting a weakened China over the previous decades.

However, the participating powers did not function evenly. The United States, Britain and Japan played decisive roles. These three were the only major naval powers after the Great War, and the issue of naval disarmament was of equal importance to the Chinese problems at the conference. Indeed, the conference has also been called the “Washington Naval Conference”. The three nations also had significant interests in the outcome of the Chinese issues under discussion. It was for those two reasons that the three nations had a significant say in the negotiations.

Outline of Its Achievements

In terms of naval issues, the conference negotiated the Five-Power Treaty, the first ever naval disarmament treaty that practically limited the total tonnage and quality of capital ships (battle ships over 10,000 tons) and aircraft carriers possessed by great powers. The treaty was signed by the three major naval powers mentioned above, plus France and Italy. Four of these nations (with Italy being the exception) possessed islands in the Pacific, and also signed the Four-Power Treaty, promising a mutual respect of each power’s possessions in the region. The treaty also ended the Anglo–Japanese Alliance, the continuance of which the United States objected to. As a result of the two mutually related pacts, the likelihood of war among the great powers in the region decreased greatly.

The primary outcome regarding China was the Nine-Power Treaty, though the agenda was rather vague in terms of both the intensity of the negotiations and the clarity of the achievements. The treaty encompassed a pledge by the eight other attending powers towards China that they would neither expand their existing privileges nor earn new exclusive rights in the country, such as leased territory and railroads, or a comprehensive preferential right to investments in a certain area in China. With this and some other related pacts, they considered themselves committed to cooperating to improve China’s status. By the same token, through the intermediation of the United States and Britain, China and Japan agreed to settle the bilateral disputes that had originally arisen from Japan’s occupation of the Shantung Peninsula in China in 1914. When the Great War broke out, Germany had a leased territory and railroad in the peninsula and the Japanese troops captured them.

Details of Naval Disarmament Issues

The naval disarmament was the most successfully concluded agenda item for the conference, and this section will specifically explain the negotiations in some detail.

Despite the war ending, the United States and Japan continued their large-scale naval programs, which had begun during the war. Consequently, Britain was forced to try and match them. This arms race situation was the immediate reason the Americans called the conference. The race was causing instability in international politics in the region; it was also a significant burden on the fiscal health of the nations involved. Public opinion also demanded large-scale disarmament, especially in the United States. Thus, binding themselves with a naval limitation treaty appeared to be the only rational choice for any of the three nations. The participation of France and Italy was required to relieve Britain’s fear of being the only European nation bounded by a naval treaty.

The final treaty was, however, not reached smoothly. At the center of the hard bargain was the contradiction between the naval strategies of the United States and Japan, which made it challenging to satisfy both, as their navies considered the other the most possible enemy.

Charles Evans Hughes (1862-1948), the United States secretary of state, took the initiative in negotiating the Five-Power Treaty. Hughes proposed a dramatic plan for naval disarmament that was composed of two elements. The first was a total prohibition of capital ship construction for the next ten years, which was to include the scrapping of all vessels of that kind in the process of being built. The second was the introduction of a fixed total tonnage ratio of capital ships respectively possessed by the United States, Britain, and Japan, as 10 : 10 : 6. With this proposal, Hughes succeeded in lowering an “anchor” that became a strong standard for how the conference should tackle the naval issues.

Britain had the worst hand based on Hughes’s limitation ratio. Although their fleets contained many warships which were becoming obsolete, the British could have claimed some superiority over the United States based on the fleets on the sea. In fact, the Japanese delegation initially insisted that the actual ratio of the existing naval strengths of Britain, the United States and Japan should be 147 : 100 : 70.5. The British, however, accepted all basic lines of the American proposal. For Britain, the worst possible scenario was a continuation of the naval race with the United States and Japan, a race in which the Royal Navy could only reach third place. In contrast, the American proposal offered the British the assurance of naval parity between the two nations in terms of capital ships. In addition, the treaty failed to cover each nation’s total tonnage of auxiliary ships, such as cruisers. Britain put more emphasis on vessels in this class than America and Japan to maintain the long sea lines in its empire.

In this regard, the American proposal was harshest toward Japan. The Japanese navy calculated that they would require at least seventy percent of their opponent’s naval power to triumph (assuming that the main theater of such a war would be the Western Pacific, giving a home-court advantage to them). This assessment was basically consistent with that of the U.S. navy, and for that reason, the American delegation asked for dominance of 40 percent over Japan.

The Japanese delegation decided to accept the essential part of the proposal, due to the leadership of Kato Tomosaburo (1861-1923), the chief delegate, a full admiral, and the serving navy minister of Japan. Kato stifled vigorous protests from the Japanese naval officers in attendance, expounding on the need for such a treaty in terms of a good relationship with the United States as well as national financial health. In addition, as compensation for the “inferior” naval strength ratio, Kato succeeded in inserting article XIX into the Five-Power Treaty, a clause which banned further fortification of islands claimed by the United States, Britain, and Japan in the Pacific. Kato’s effort to successfully embed the Japanese navy in a wider international institution was not perfect, but it took another decade for the dissenters among the Japanese navy to start challenging the treaty, which they did in 1930, when the London Naval Conference was held to settle the remaining problem of the limitation of auxiliary vessels.


Tadashi Nakatani, Teikyo University


Section Editors: Jan Schmidt; Sōchi Naraoka