Deterrence of nuclear use through the threat of retaliation could be highly problematic in many plausible conflict scenarios with nuclear-armed regional adversaries. This could compel U.S. leaders to temper their military and political objectives if they come into conflict with these states. This book examines the reasons behind this important shift in the international security environment and its strategic and force planning implications.Deterring nuclear use by regional adversaries such as North Korea could be problematic in some situations. This book examines the strategic and force planning implications of this shift in the international security environment.