There is consensus among many U.S. national security professionals and academics: We all just need to learn to live with a nuclear North Korea. This consensus is wrong.
North Korea cannot be deterred from using its nuclear weapons. A strategy based on deterrence may help to avoid conflict in the near term, but it likely would lead to a far deadlier one in the not-so-distant future.
U.S. leaders and policy makers are optimistic about deterrence because of the caution that charachterized the relationship between the United States and the Soviet Union during the Cold War. After a series of potential catastrophes culminating in the Cuban Missile Crisis, both sides were compelled to create a more stable deterrence framework. The structure was bi-polar, limiting complexity. Both sides operated sophisticated nuclear triads, ensuring that one could not destroy the other in a surprise attack and ensuring mutually assured destruction. Both sides were governed by teams of experienced strategists and policy makers, many of whom had witnessed the devastation of World War II and sought not to repeat it. Core components of the nuclear arsenals were separated by vast distances, affording decision makers some time to try to understand and react to events. Both sides possessed advanced early warning systems and command-and-control capabilities. Both sides had well-exercised weapons-handling procedures, and designed their weapons with redundant safety features. The highest levels of government established direct lines of communications and non-governmental and non-military parties came in to work on the nuclear weapon problem.
None of these conditions exist in Northeast Asia.
If North Korea were to develop a fully deliverable nuclear arsenal, it will be on a hair trigger alert status for years. Poorly prepared North Korean decision makers would be subjected to extreme compressions of time as U.S. nuclear and conventional forces operated within close proximity, and with the ability to strike with little or no warning. North Koreans would be in a use-them-or-lose-them position with their nuclear arsenal, with the incentive to use nuclear weapons early in the event of any conflict. The situation becomes more complex when one considers that South Korean infrastructure (port facilities, for example) could be a target if the Kim Jong Un felt he could use them to force the United States into negotiations.
The United States has little knowledge of how North Korea’sl eadership would act in a pressure-cooked situation. Outside of Kim Jong Un’s inner circle, almost nothing is known about the North Korean regime. How are decisions made? Who wields power? Who has the ability to influence?
Proponents of deterrence assert that Kim is rational, but nuclear scenarios require more than rationality. There also must be predictability. North Koreans have lived isolated lives and have a different sense of the world. A dictator who executes family members for offering “insufficiently enthusiastic praise” is unlikely to listen to dissenting views or to accept unwelcome news or advice.
Deprived of both facts and opinions, the North Korean perspective may seem rational. But North Koreans could cause war with outside nations anytime. Kim’s regime is under extreme stress at the moment, and when coupled with a scenario involving compressed time, he could believe that he is being forced to act aggressively.
The time has come to face some hard truths. The United States cannot just live with a nuclear North Korea—not one that can incinerate U.S. citizens. Because at some point—whether driven by aggression, fear, operational mishap, or misinformed decision—Kim likely will use his weapons.
 See Jung H. Pak’s segment on the Ten-Foot-Tall Baby in her Brookings Institution essay “The Education of Kim Jong Un.”
 Sagan, Scott “The Korean Missile Crisis: Why Deterrence Is Still the Best Option,” Foreign Affairs, November/December 2017.
Mr. Kapsaroff is a former surface warfare officer currently working as a strategist on Wall Street.