Together, the treaties signed at the Washington Naval Conference served to maintain the status quo in the Pacific: they recognized existing interests and did not fundamentally change them. At the same time, the United States secured agreements that strengthened its existing policy in the Pacific, including the open door policy in China and the protection of the Philippines, while limiting the scope of Japanese imperial expansion as much as possible. In 1921, U.S. Secretary of State Charles Evans Hughes invited nine countries to Washington, D.C. to discuss the reduction of the navy and the situation in the Far East. The United Kingdom, Japan, France and Italy were invited to participate in the discussions on the reduction of naval capacity, while Belgium, China, Portugal and the Netherlands were invited to participate in the discussions on the situation in the Far East. The Washington Naval Conference produced three important treaties: the Five Powers Treaty, the Four Powers Treaty, and the Nine Powers Treaty. The Five Powers Treaty, signed by the United States, the United Kingdom, Japan, France and Italy, has been the cornerstone of the Navy`s disarmament agenda. He called on each of the countries concerned to maintain a fixed tonnage ratio of warships that would allow the United States and the United Kingdom 500,000 tons, Japan 300,000 tons and France and Italy 175,000 tons each. Japan preferred to allocate tonnage to a ratio of 10:10:7, while the U.S. Navy preferred a ratio of 10:10:5. The conference finally adopted the limits of the 5:5:3 ratio.

Since the United States and the United Kingdom maintained navies in the Pacific and Atlantic to support their colonial territories, the Five Powers Treaty granted the two countries the highest tonnage quotas. The treaty also called on the five signatories to stop building capital ships and reduce the size of their navies by scrapping older ships. In addition to multilateral agreements, participants concluded several bilateral agreements at the conference. Japan and China signed a bilateral agreement, the Treaty of Shangtung (Shandong), which returned control of the province and its railways to China. Japan had taken control of the German region during World War I and retained control in the following years. The combination of the Treaty of Shangtung and the Nine Powers Treaty was intended to reassure China that its territory would not be further threatened by Japanese expansion. In addition, Japan agreed to withdraw its troops from Siberia, and the United States and Japan formally agreed to equal access to cable and radio equipment on the Japanese-controlled island of Yap. The latest multilateral agreement of the Washington Naval Conference, the Nine Powers Treaty, marked the internationalization of the US open door policy in China. The treaty promised that each of the signatories – the United States, the United Kingdom, Japan, France, Italy, Belgium, the Netherlands, Portugal and China – would respect China`s territorial integrity. The treaty recognized Japanese rule in Manchuria, but also reaffirmed the importance of equal opportunity for all nations doing business in the country. China, for its part, has agreed not to discriminate against any country that wants to do business there.

Like the Four Powers Treaty, this Treaty on China called for further consultations among the signatories in the event of a violation. As a result, it did not have a method of enforcement to ensure that all powers complied with its provisions. Between 1921 and 1922, the world`s greatest naval powers gathered in Washington, D.C. for a conference on the disarmament of the sea and ways to reduce growing tensions in East Asia. Although the Five Powers Treaty controlled the tonnage of each navy`s warships, certain classes of ships remained unrestricted. As a result, a new race to build cruise ships arose after 1922, prompting the five countries to return to the negotiating table in 1927 and 1930 to fill the remaining gaps in the treaty. In the Four-Power Treaty, the United States, France, the United Kingdom and Japan agreed to consult with each other in the event of a future crisis in East Asia before taking action. This treaty replaced the Anglo-Japanese Treaty of 1902, which had caused some concern among the United States. .