After decades of solely relying on the United States for its national security needs, Japan has begun to actively develop and deepen its security ties with a growing number of countries and actors in the Asia-Pacific region and Europe, a development that has further intensified under the Shinzo Abe administration. This book provides a comprehensive analysis of the motives and objectives from both the Japanese and the partner-countries' perspectives, and asks what this might mean for the security architecture in the Asia-Pacific region, and what lessons can be learned for security cooperation more broadly. It examines in detail Japan's partnerships with Australia, India, countries and multilateral security fora in East Asia, as well as with the EU and some of its member states. Since the mid-2000s under LDP and DPJ administrations, bilateral security partnerships accelerated and today go beyond non-traditional security issue areas and extend far into traditional security and military affairs, including the exchange and joint acquisition of military hardware, military exercises, and capacity building. It is argued, that these developments will have wide ranging implications for the security architecture in the Asia-Pacific, all of which are explored in this collection. This book is for those interested in Japan's security policy beyond the US-Japan security alliance, and non-US centred bilateral and multilateral security cooperation. It is ideal for undergraduate and graduate level courses on regional security cooperation and strategic partnerships, and Japanese foreign and security policy.