How does a nation become a great power? A global order was emerging in the nineteenth century, one in which all nations were included. This book explores the multiple legal grounds of Meiji Japan's assertion of sovereign statehood within that order: natural law, treaty law, international administrative law, and the laws of war. Contrary to arguments that Japan was victimized by 'unequal' treaties, or that Japan was required to meet a 'standard of civilization' before it could participate in international society, Howland argues that the Westernizing Japanese state was a player from the start. In the midst of contradictions between law and imperialism, Japan expressed state will and legal acumen as an equal of the Western powers in international incidents in Japanese waters, disputes with foreign powers on Japanese territory, and the prosecution of interstate war. As a member of international administrative unions, Japan worked with fellow members to manage technical systems such as the telegraph and the post. As a member of organizations such as the International Law Association and as a leader at the Hague Peace Conferences, Japan helped to expand international law. By 1907, Japan was the first non-western state to join the ranks of the great powers.