Evaluating Japan’s defense cooperation agreements and their transformative potential: upgrading strategic partnerships with Australia and the UK

Abstract Japan’s defense cooperation agreements (DCAs) have been proliferating in recent years. Despite Japan’s harsh security environment, rather than expanding formal military alliances beyond its sole US ally, DCAs have emerged as a crucial instrument deployed by Japan to strengthen bilateral and minilateral defense relations with various partners. How do we make sense of Japan’s growing activism in forging DCAs? Yet, there does not currently exist a framework to systematically evaluate these DCAs, nor is there a detailed assessment of the utility of these DCAs in transforming Japan’s partnerships with like-minded states. This article proposes an analytical matrix derived from several key performance indicators and applies it to evaluate how Japan’s use of DCAs has transformed its defense relationships with two key strategic partners, Australia and the UK.