This book examines the rights and duties of states across a broad spectrum of maritime security threats. It provides comprehensive coverage of the different dimensions of maritime security in order to assess how responses to maritime security concerns are and should be shaping the law of the sea. The discussion canvasses passage of military vessels and military activities at sea, law enforcement activities across the different maritime zones, information sharing and intelligence gathering, as well as armed conflict and naval warfare. In doing so, this book not only addresses traditional security concerns for naval power but also examines responses to contemporary maritime security threats, such as terrorism, weapons of mass destruction, piracy, drug-trafficking, environmental damage and illegal fishing. While the protection of sovereignty and national interests remain fundamental to maritime security and the law of the sea, there is increasing acceptance of a common interest that exists among states when seeking to respond to a variety of modern maritime security threats. It is argued that security interests should be given greater scope in our understanding of the law of the sea in light of the changing dynamics of exclusive and inclusive claims to ocean use. More flexibility may be required in the interpretation and application of the UN Convention on the Law of the Sea if appropriate responses to ensure maritime security are to be allowed.