The site of great power rivalry has shifted from Europe to Asia in the second nuclear age characterized by a multiplicity of nuclear powers with criss-crossing ties of cooperation and conflict, the fragility of command and control systems, the critical importance of cyber security, threat perceptions between three or more nuclear-armed states simultaneously, asymmetric perceptions of the military and political utility of nuclear weapons, and the resulting greater complexity of deterrence relations between the nine nuclear-armed states. The strategic boundary between nuclear warheads and conventional precision munitions is being eroded, as is that between the nuclear, cyber, and space domains. Most concerningly, the overall risks of nuclear war have grown, with more countries with weaker command and control systems in more unstable regions possessing these deadly weapons, terrorists wanting them, and vulnerability to human error, system malfunction, and cyber-attack.