This book undertakes an in-depth examination of the diversity in international approaches to the navy-coastguard nexus. It considers the evolving global maritime security landscape and the emergence and proliferation of maritime law enforcement agencies—collectively referred to here as “coastguards”—performing peacetime constabulary duties alongside navies. Through a cross-regional study of various countries worldwide, including those in Asia and Europe, this book reveals that there is no one optimal, “one size fits all” organizational structure. Instead, there is a wide array of drivers that influence a nation-state’s maritime security architecture and its organizational approach to managing security at sea, or broadly speaking, securing its national maritime interests.