Deterring a Nuclear-Armed Adversary in a Contested Regional Order: The “Trilemma” of U.S.–North Korea Relations

North Korea’s dogged pursuit of a nuclear and ballistic missile capability has never been the sole reason for its confrontational relationship with the United States. The issue sits at the intersection of multiple narratives about where North Korea fits in U.S. strategy toward Asia. From the U.S. perspective, North Korea is a deterrence challenge, a proliferation threat, and a dangerous wildcard in the increasingly contested regional order. Each of these views of North Korea implies different policy priorities, and each favors different ways of addressing the North Korean nuclear threat. The degree to which U.S. policy emphasizes different tools of statecraft depends on how each of these three narratives defines the North Korea problem.

This “trilemma” helps explain why all past attempts to solve the North Korean nuclear puzzle have come up short. The complexity of the situation presents hard choices, which successive U.S. presidents have preferred to avoid, even though doing so has allowed the problem to grow worse and more disadvantageous for the United States over time. But “passing the buck” on a decisive course of action against North Korea is becoming untenable. President Donald Trump may not have the luxury of passivity and risk avoidance toward the North Korean nuclear problem. The United States is gradually being forced to take a more decisive approach that necessarily involves greater risk. But will it primarily be a domestic political, geopolitical, or military risk?

The remainder of this essay will outline three different narratives about how the North Korean nuclear problem matters in U.S. strategy—as a war threat, as a nuclear proliferation threat, and as a threat to the regional order. Each section will identify the key priority within a narrative, as well as the relative importance of different tools of policy, from diplomacy and sanctions to deterrence and preventive strikes. The essay then highlights how these narratives exist as an uneasy triangle or trilemma: any attempt to definitively address the North Korean nuclear problem from one perspective may require sacrificing a priority built into other perspectives.

A Threat to Successful Deterrence

Especially in defense circles, the highest priority for U.S. and regional interests has long been maintaining stability through deterrence. When deterrence-based stability is the overriding priority, barring a diplomatic miracle, the United States must effectively plan to live with a nuclear-armed North Korea. Diplomacy can help bolster deterrence but never undermine it. International sanctions are a peripheral concern. Preventive strikes on nuclear facilities are possible, but only if policymakers truly believe doing so would have a future deterrence benefit, which is debatable. A stability-first strategy toward North Korea involves preventing war through deterrence and getting a better grip on the provocation problem.

First, deterrence of major war is a constant work in progress, not something to be taken for granted simply because the United States is the bigger power. Deterrence depends on a dynamic formula involving capabilities, interest, and resolve—what it takes to deter invasion or military adventurism changes depending on what North Korea does and has. North Korea tinkering with the size and composition of its military arsenal should compel the United States to frequently revisit contingency planning, force presence, and strategic signaling considerations.

Second, whereas strategic deterrence has held on the Korean Peninsula for more than a half-century, tactical deterrence has repeatedly failed. North Korea has a long history of resorting to small-scale, isolated acts of militarized violence (“provocations”) against the United States and South Korea. U.S. policymakers have historically viewed these provocations as undesirable but basically acceptable as long as war did not break out anew.¹ But provocations are becoming a newly unacceptable problem because of pressures from Seoul. Since 2010, when North Korea twice attacked the South, the latter vowed “manifold retaliation” against North Korea the next time it engaged in violent provocations, and South Korea has been adjusting its military capabilities, doctrine, and force posture to make good on that threat.² In the wake of the 2010 attacks, South Korean public discourse...