This chapter traces Japan’s status concerns from the late 19th century leading up to the 1922 Washington Naval Treaty. It examines Japan’s approach to naval power after the First World War and derives expectations for how Japan would react to an international agreement such as the Washington Naval Treaty from two competing perspectives: material interests and IST. It tests these hypotheses through a detailed account of Japan’s approach to the Washington Conference of 1921–1922. It finds that although Japan faced a growing threat from the United States in the Western Pacific, Japan accepted greater restraints on warship construction in order to maintain its access to the great power club, alongside Britain and the United States, as part of the ‘Big Three’ at the conference. Subsequently, the US Immigration Act of 1924, which unprecedentedly banned Japanese immigration to America, served as a major betrayal of Japan’s sacrifices for the sake of the international order, thus altering Japanese perceptions of the openness and fairness of the Washington system. It convinced many moderates that the West would never consider Japan its equal, and it empowered anti-treaty factions begin the costly process of abrogating Japan’s commitment to the Washington system.