and it is impossible to know how he would respond. Any military strike against North Korea, the first since the Korean War, even with clear signaling from the United States that it was not a prelude to a decapitation attempt, would present Kim with a use-or-lose dilemma, in which he would have to choose between using nuclear weapons first, or die knowing that his weapons failed at deterring an attack and ensuring regime survival.
Instead of denuclearization and a contrite Kim Jong Un, a preemptive military strike on North Korea would be counterproductive, with the potential to ignite a nuclear war and inflict high political and economic costs on the United States and trigger an unprecedented humanitarian crisis at a magnitude that the region and the international community would be ill-equipped to handle.
First, if Kim survived and North Korea continued to exist as a state, his commitment to maintaining his weapons would likely be reinforced by the U.S. attack, and he would use the offensive to rally the North Korean people around him. The pursuit of nuclear weapons and the existential war against the United States are in Kim’s DNA; his grandfather became interested in a nuclear program in the devastating aftermath of the Korean War. A U.S. attack would be a fresh reminder of the need for nuclear weapons for younger generations of North Koreans who have only known a nuclear state and for whom their failed bid to take over the South by force in 1950 has been only a historical memory. An attack by the United States, limited or not, would validate decades-old regime propaganda about U.S. intentions toward their country and bolster Kim’s status as a protector of the nation.
Second, Kim likely would respond to a limited strike with symmetrical military action, such as artillery strikes against South Korea’s islands along the maritime border or shorter-range ballistic missile launches against South Korean and Japanese targets, in order to maintain the initiative and to show that he will not be intimidated. Kim’s aggressive personality, his desire to project strength and demonstrate resolve to protect his domestic standing, coupled with his efforts over the years to improve North Korea’s conventional military capabilities and diversify his nuclear arsenal and its launch locations, all suggest that Kim would be inclined to respond to strikes on North Korea, even at the risk of escalation.
Third, if a U.S. strike resulted in Kim’s death or ouster, his removal would not provide a guarantee that North Korea will denuclearize. The new leadership could seek to develop nuclear weapons covertly and share the Kim family’s view of a nuclear arsenal as a way to maintain leverage and protect itself in a hostile strategic environment. Our limited visibility into the full scope of North Korea’s weapons program compounds the problem.
Fourth, a strike not premised on an imminent threat would draw widespread international condemnation from U.S. partners and allies as an illegal act of aggression, contravening the Charter of the United Nations and international law. It would damage the U.S. alliance with South Korea and prompt Moscow and Beijing to increase economic aid to North Korea and dial back U.N. sanctions to prevent regime collapse, claiming that Washington, not Pyongyang, is threatening regional stability. Beijing might also intervene militarily to assert its role and protect its interests in a quickly evolving situation.
Finally, if a U.S. first strike led to a conventional or nuclear war, the humanitarian and economic costs would be unacceptably high. The Seoul metropolitan area—located only thirty-five miles from the North Korean border, with about twenty-five million inhabitants, around two hundred thousand of whom are American citizens or soldiers stationed in nearby Pyeongtaek (and around a million Chinese tourists, students, and businesspeople at any given time)—would be difficult to defend against conventional strikes and virtually impossible to defend against strikes involving weapons of mass destruction. Tokyo, with a population of around thirty-eight million, would be similarly difficult to defend. The Congressional Research Service estimated that Pyongyang could blanket Seoul with ten thousand artillery rounds per minute and kill three hundred thousand South Koreans within a few days. North Korea’s chemical weapons could potentially kill up to 2.5 million people in South Korea. An article on the website Vox grimly summed up the carnage: “Men, women, and children would very literally choke to death in the streets of one of the world’s wealthiest and most vibrant cities. It would be mass murder on a scale rarely seen in human history.”