The Reason the 'Washington Naval Disarmament System' Could Operate for 15 Years

The 1922 Washington Naval Disarmament Conference, attended by the victors of World War I: the United States, Great Britain, Japan, France, and Italy.

The naval disarmament system was maintained for nearly 15 years, capping the fleet sizes of major powers. [Photo: Wikipedia]

World War I, an unprecedented 'total war,' resulted in nearly 10 million casualties in about four years. As a reaction to the horrors, voices for arms reduction emerged globally in the 1920s, with a desire never to repeat such a war. Representative examples of this trend include the Washington Naval Treaty of 1922, where five countries—the US, Britain, Japan, France, and Italy—agreed to limit their naval forces; the Locarno Treaties of 1925, in which European nations pledged to maintain the status quo of their borders; and the Kellogg-Briand Pact of 1928, which declared war itself illegal and was signed by over 60 countries. The World Disarmament Conference, which opened in Geneva in February 1932 with representatives from about 60 nations, was also a product of this era's aspirations.

However, the fates of Washington and Geneva diverged. The Washington Naval Disarmament system, which began with the Washington Conference in 1921 and was reinforced by the London Conference in 1930, actually operated for nearly 15 years until Japan gave notice of its withdrawal in 1934—and legally until its expiration in 1936—capping the fleet sizes of major powers. In contrast, the Geneva Disarmament Conference, after dragging on for two years, ended in 1934 with no treaties whatsoever. Disarmament in the interwar period is often collectively referred to as a 'history of failure.' This is not incorrect, as all treaties eventually collapsed and World War II broke out. However, when judged not just by the conclusion of agreements but by the criteria of 'sustainability and implementation,' the two cases followed diametrically opposed paths. What caused this difference?

German Opposition, Failure of Geneva Disarmament with 60 Nations Participating

The reason the Washington Naval Disarmament system could persist for 15 years, despite the collapse of interwar disarmament in the late 1930s, was due to a confluence of conditions: the rising power's strategy of seeking status, domestic political balance supporting defense budget cuts, and linkage with other strategic interests. First, the rising power chose 'status-seeking through partial military restraint.' Japan, while accepting a militarily disadvantageous ratio of 60% of capital ships compared to the US and Britain, sought civilized status alongside Western powers. It later pursued status enhancement by increasing the ratio of auxiliary combat ships to nearly 69% within the framework of the Washington disarmament system. Underlying this was an existential anxiety stemming from the possibility of being ostracized as the sole non-white great power since the late 19th century. It was an unsatisfactory condition, but one that was accepted and inwardly developed.

The second condition was the domestic political balance in Japan that underpinned this military restraint. During this period, party cabinets, continuing from the Kenseikai and Minseitō, maintained a non-expansionist line, linking fiscal austerity, a return to the gold standard, and access to the US capital market with disarmament. Prime Minister Osachi Hamaguchi, Finance Minister Junnosuke Inoue who pushed for austerity and deflation, and Foreign Minister Kijūrō Shidenhara, who upheld the line of international cooperation, were central figures. Hardliners within the navy, led by Kanji Kato, protested, considering even the 60% and later 70% ratio of capital ships a humiliation, but they were compelled to obey the political dominance of the existing elite. As long as the domestic coalition supporting disarmament remained alive, the hardliners' discontent could not shake the disarmament system, despite being triggered by the racial humiliation of the US Immigration Act of 1924 targeting Japanese immigrants.

The domestic political foundation for disarmament was not unique to rising Japan. The three Republican presidents of the United States—Harding, Coolidge, and Hoover—prioritized the domestic economy, national debt repayment, and tax cuts over naval expansion. It was Congress, not the Navy, that decided the size and budget of the military and the ratification of treaties. Congress was indifferent to the cruiser expansion consistently demanded by the Navy and overwhelmingly ratified the Washington Treaty. Although Congress approved the construction of eight large cruisers in 1924, only one was actually funded by the end of 1926. Coolidge stated, "Our main problem is domestic, and fiscal stability is the first requirement of sound government," advocating for "bold but orderly retrenchment." Even after the US and Britain came under Roosevelt's administration, and after Japan turned to revisionism (a policy of altering the international political order through military force, diplomacy, etc.), they attempted to maintain the Washington system. Ultimately, the sustainability of multilateral disarmament depended not on the goodwill or deviation of any single leader, but on the survival of the domestic coalition that supported it.

The third condition was the 'linkage' with other strategic interests. During the Washington Conference, the US achieved its goal of dissolving the Anglo-Japanese Alliance by concluding the Four-Power Treaty among the US, Britain, Japan, and France in 1921. From the US perspective, the Anglo-Japanese Alliance was a mechanism that encouraged Japanese adventurism in Asia. The US bound naval arms limitations and its Pacific policy as "indispensable parts of the same whole," controlling the agenda by running large multilateral forums discussing disarmament in parallel with small US-British-Japanese secret groups. The US position was that it would not accept any naval treaty unless the Anglo-Japanese Alliance was abolished. Japan, in return for accepting the unfavorable capital ship ratio, gained the freezing of fortifications in US territories in the Pacific, excluding Hawaii, Alaska, and the Panama Canal.

Thus, when these three conditions—the rising power's concept of status, the domestic political basis for disarmament, and the linkage with other strategic interests—aligned, the five-power system could function, albeit temporarily, on the balance primarily among the three core powers: the US, Britain, and Japan.

The failure of the Geneva Disarmament Conference can be explained by the absence of these conditions. While Japan in the Washington Naval Disarmament system was a rising power that chose status-seeking through restraint, Nazi Germany, which came to power in 1933, chose status-seeking through military buildup from the outset. Even before taking power, the Nazis fiercely criticized the Geneva Disarmament Conference in 1932. France's domestic political support was also directed towards its own security rather than disarmament. France insisted on "no disarmament without security" and demanded US guarantees for European defense, but the US Senate was unlikely to accept this. France could not disarm without security guarantees, and Germany could not accept a system that limited its military capabilities.

New Points of Exchange, Such as Arctic Routes and Climate Change

The 'linkage' with other strategic interests was also absent. In Geneva, which addressed the reduction of land, sea, and air forces simultaneously, it was nearly impossible for over 60 countries to exchange strategic interests. They could not agree on whether tanks, aircraft, and chemical weapons were offensive or defensive, and each country argued for classifications favorable to itself. Unlike the Washington Naval Disarmament system, which focused on a measurable single military category (capital ship tonnage and gun caliber) and was limited to five participating nations, Geneva lacked even a common point of reference for agreement. Coupled with Britain's political insensitivity, which failed to recognize the revisionist threat from Germany, the strategic balance achieved between the US, Britain, and Japan in the Washington system could not be formed between Britain, Germany, and France.

The implications of interwar disarmament for the 21st century are not simple. Regarding the first condition, the strategy of rising powers, China today exhibits a different revisionism than Japan and Germany in the interwar period, as it does not deny the existing order entirely but pursues selective criticism and partial revision. Considering the US, China, and Russia, the second condition, the domestic political basis, is also not aligned to support disarmament. While the Trump administration's second term National Security Strategy hinted at a cautious selection and concentration of military force, actual policies are moving in the opposite direction, as seen in the US-Iran war and planned defense budget increases.

However, the third condition, linkage with other strategic interests, remains a medium- to long-term variable. The opening of Arctic routes, climate change, and the impact of artificial intelligence on military, economic, industrial, and technological capabilities may create new points of exchange from which great powers can derive mutual deterrence benefits.

The implication from the interwar period is not that disarmament is impossible, but that disarmament requires a supporting political substructure. While the short-term outlook for disarmament systems is bleak, it remains to be seen whether this substructure will be realigned in the context of a predicted prolonged global crisis. Although difficult, South Korea too will need to carefully choose whether to be on the side that creates these conditions or on the side that pays the cost of their absence.

Anglo-Japanese AllianceA military alliance signed in 1902 between Britain and Japan to counter Russian expansion in Asia. Japan used this treaty as a springboard to achieve victory in the Russo-Japanese War and the colonization of Korea. After World War I, under pressure from the US, which was wary of Japan's rise, it was replaced by the Four-Power Treaty concluded during the Washington Conference in 1921.

Washington ConferenceA consultative body on naval disarmament and Pacific and Far East issues, convened in November 1921 under US leadership. The Five-Power Treaty was signed, limiting the total tonnage of capital ships to a ratio of US:UK:Japan:France:Italy = 5 : 5 : 3 : 1.67 : 1.67. It stipulated the maintenance of the colonial status quo and respect for Chinese sovereignty, forming the backbone of the East Asian order for about 15 years.

Geneva ConferenceA large-scale conference held in 1932 under the auspices of the League of Nations to attempt the disarmament of all land, sea, and air forces. France's priority on security clashed directly with Nazi Germany's demand for military parity immediately after coming to power, leading to the conference's demise the following year when Nazi Germany withdrew from both the conference and the League of Nations.

Oh In-hwan is a Senior Research Fellow at the East Asia Institute (EAI). He also serves as Director of the EAI Secretariat and lectures at Seoul National University's Department of Political Science and International Relations. He holds a Ph.D. in Political Science from Boston College and previously served as an Assistant Professor at the College of William & Mary. His primary research areas include international security, foreign policy, and US-China relations.

[Source: JoongAng Ilbo]https://www.joongang.co.kr/article/25440282