Why the North Korea–U.S. Nuclear Deal Collapsed: Psychological Gaps Behind Structural Barriers

In 2018 and 2019, leaders of North Korea and the United States held unprecedented summits in Singapore and Hanoi to negotiate denuclearization. Despite favorable diplomatic conditions and symbolic gestures, both efforts failed. A study by Seok Joon Kim of Korea University, published in Political Psychology, explores why these negotiations collapsed—not due to structural obstacles alone, but because of psychological gaps in how signals were perceived by both sides.

Between 2017 and 2019, North Korea and the United States transitioned from threats of "fire and fury" to direct engagement, as symbolized by the summits in Singapore and Hanoi. While many scholars attributed the negotiation breakdown to structural distrust or North Korea’s intent to retain its nuclear arsenal, Kim proposes a novel explanation rooted in cognitive psychology and international relations theory: a “perceptual gap” between the signaler (North Korea) and the receiver (United States).

The author introduces the “dilemma of costly signals,” a situation where a state must take risks to make its intentions credible, but those very risks—such as dismantling nuclear capabilities—jeopardize the state's own security. For North Korea, sending credible signals of denuclearization (e.g., dismantling Punggye-ri test site or halting missile tests) implied severe vulnerabilities, especially without firm security guarantees. However, U.S. policymakers frequently underestimated the level of risk North Korea faced, demanding gestures—like a full nuclear inventory or compliance with the “Libya model”—that Pyongyang deemed excessive.

Kim identifies three psychological biases behind the U.S. discounting of North Korea's actions: (1) Overlooking Sacrifices, the underestimation of Pyongyang’s security fears; (2) Nice Guy Fallacy, the overconfidence that North Korea should trust U.S. intentions not to exploit vulnerability; and (3) Prior Belief, the entrenched skepticism from previous failed agreements. These factors widened the gap between what Pyongyang was willing to offer and what Washington considered credible.

Contrary to previous rationalist models that assumed states interpret signals uniformly, the study emphasizes how subjective perceptions and historical distrust distort signal credibility. In Kim's framework, even objectively costly actions like site destruction or moratoriums fail if the receiver doubts the signaler’s sincerity. This framework draws from neoclassical realism, arguing that cognitive filters—beliefs, past experiences, and threat perception—shape state responses more than assumed in traditional signaling theory.

This nuanced understanding also reveals the asymmetry in power and expectations. The stronger side (U.S.) expects more substantial proof from the weaker side (North Korea), while the latter hesitates to further compromise security. This dynamic leads to mutual misrecognition: Pyongyang believes its actions are enough; Washington perceives them as insufficient.

Kim's analysis suggests that resolving the Korean Peninsula nuclear issue requires more than structural diplomacy or coercive strategies. It demands active efforts to reduce the perceptual gap between adversaries through trust-building measures and third-party facilitation. The article implicitly calls for policymakers to incorporate psychological realism into negotiation strategies, highlighting that misunderstanding of intentions—not merely opposing interests—can derail even the most promising diplomatic openings. As future administrations consider re-engagement, acknowledging the role of perception could be key to avoiding past pitfalls.

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