The Japan-US alliance has continued to deepen and develop for around sixty years, responding to the security environment of the times. But today, the security order of the Asia-Pacific region is at an important turning point. China’s maritime activities are only intensifying, causing growing instability in the regional maritime security environment. As the existing order of the Asia-Pacific region is now being threatened, the Japan-US alliance is an “alliance of hope” for peace and prosperity. In this book, the authors analyze the present conditions of the alliance and discuss its future direction from this perspective of maintaining the maritime security order in the Asia-Pacific region. Together with the diplomatic and security policies of Japan and the US, and of China, their research subjects include the policies of India, Australia, South Korea, Russia, and ASEAN, which are the main players in the oceans of the region, and they derive important hints for the future of the Japan-US alliance.