Abstract: India–Japan security cooperation is a critical component in the evolving security mechanism of the Indo-Pacific region. Both states are secondary states in the international system that opposes one country’s emergence as a regional hegemon. China’s rise and her ambition to dominate the Indo-Pacific would affect the security interests of India and Japan. The U.S., the current preponderant power in the region, seems unable to contain China by itself. So it is looking for strategic partnerships with regional countries who are militarily capable of challenging China, and persuading them to balance China. In this regard, the two powerful states in China’s own backyard – Japan in the western Pacific and India in the Indian Ocean – have come together to counter the Chinese hegemony in the Indo-Pacific. In this effort, they have gradually built up naval cooperation sans a formal military alliance. They follow soft balancing strategies over hard balancing ones because neither wants to antagonise China. Similarly both countries seek to expand their presence through mutual cooperation beyond South-east Asia. This article explains the nature and context of soft power balancing strategies and the manner in which the India–Japan maritime security cooperation has evolved over the last two decades. Full text available here.