Since the late 1990s, the Japan Coast Guard (JCG) has countered a myriad of 'outlaw' threats at sea including piracy, terrorism, the proliferation of Weapons of Mass Destruction (WMD) and the threat posed by 'rogue states'. Japan's innovative strategy has transformed maritime security governance in Southeast Asia and beyond.1. Introduction 2. Japan: An Innovative Power? 3. Defining Outlaws 4. The Root Causes of Outlaw Behaviour 5. North Korean 'suspicious ships' 6. Piracy in Southeast Asia and the Gulf of Aden 7. Counter-terrorism and Proliferation at Sea 8. ConclusionLindsay Black is Lecturer in the International Relations of East Asia at the Leiden University Institute for Area Studies (LIAS), the Netherlands. His published work includes articles in The Pacific Review, International Relations, and International Relations of the Asia Pacific.