Explaining Japan's post-Cold War security policy trajectory: maritime realism.

Why has Japan shifted towards a more active security posture since the end of the Cold War? Japan's security policy under Prime Minister Abe has triggered numerous discussions on the changing nature of Japan as a security actor. This article identifies two independent variables—the balance of power calculations and secure access to the maritime commons—that informs Japan's security policy trajectory. It argues that Japanese strategy is best described as 'maritime realism', a posture in which liberal internationalist and realist elements draw upon principles of maritime strategy to fuse together. Japan has not only actively facilitated US commitment to maritime Asia but also focused on expanding its role in maritime security as the maritime space in the Indo-Pacific has increasingly become a contested space. While Tokyo's security policy corresponds with structural realist predictions, they have also been frequently expressed in liberal internationalist language given the peculiar nature of the role of navies. This article's findings advance theoretical debates on alliance politics and great power competition by integrating international relations and concepts in strategic studies. It also contains significant explanatory power in assessing the trajectory of Japan's defence policy since the end of the Cold War. [ABSTRACT FROM AUTHOR]