With the U.S. aircraft carrier fleet facing reduced availability, this book explores the possibility of using the submarine force in an expanded role in naval diplomacy. This work suggests that submarines have the capability to communicate a signal to an opponent state by temporarily revealing themselves tactically. This signal of hidden capacity can be tailored into a tacit bargaining strategy that can significantly influence rival navies. By examining the development of naval diplomacy over the last two hundred years, this book critically reexamines U.S. Aircraft-carrier-based diplomatic practices relative to the emerging use of rival submarine forces in asymmetrical signaling strategies. In examining Russian, British, and Chinese attempts to signal adversaries using submarines, this thesis provides context for the capacity submarines have in today's naval diplomatic setting to force large changes in opponents strategic frameworks at low cost to the initiators. Because of these findings, this book recommends increased evaluation of such activities from a diplomatic and strategic perspective and increased awareness that such signals may be aimed at our military.