North Korea's leaders have sought to dominate the Korean Peninsula since then failure to conquer the Republic of Korea (ROK) in tine Korean War. However, they have lacked the economic, political, and conventional military means to achieve that dominance, having instead come to rely on their nuclear weapon and ballistic missile programs, Today, North Korea's nuclear weapons pose an existential threat to the ROK, and they might soon pose a serious threat to the United States; even a few of them could cause millions of fatalities and serious casualties if detonated on ROK or U.S. cities. The major ROK and U.S. strategy to moderate this threat has been negotiating with North Korea to achieve denuclearization, but this effort has failed and seems likely to continue tailing. North Korean leader Kim Jong-un, despite committing to denuclearization, has continued his nuclear weapon buildup. The authors of this Perspective argue that there is a growing gap between North Korea's nuclear weapon threat and ROK and U.S. capabilities to defeat it. Because these capabilities will take years to develop, the allies must turn their attention to where the threat could be in the mid to late 2020s and identify strategies to counter it. Doing this will help establish a firm deterrent against North Korean nuclear weapon use. The authors conclude that North Korea will be most deterred if it knows that any nuclear weapon use will be disastrous for the regime-that these weapons are a liability, not an asset. Book jacket.

To secure the survival of its regime, dominate the Republic of Korea (ROK), and impose unification of the Korean Peninsula, North Korea has amassed a variety of weapons of mass destruction (WMD)-nuclear, chemical, and biological-to include nuclear and likely conventional capabilities that produce highly destructive or even lethal electromagnetic pulse. It also has diverse offensive cyber capabilities that it uses for covert and illegal purposes. The authors of this report focus on how the North could use, and does use, these weapons and capabilities to affect peacetime relations on the peninsula and to prepare for a major war with the ROK, as well as the possible effects of their employment on the military, on civilians, and on critical infrastructure. The authors present a theory of deterrence and suggest how the ROK-U.S. alliance could rein in North Korean efforts to augment or enhance its WMD and cyber capabilities and deter the North from attacking the ROK and beyond. Throughout, the authors acknowledge the uncertainties involved and argue that any effective action on the part of the ROK-U.S. alliance will require recognizing and managing those uncertainties.