North Korea has recently been implementing what might be termed a North Korean variant of Conventional-Nuclear Integration (CNI), combining conventional forces, drones, artificial intelligence (AI), and cyber and cognitive warfare capabilities with its nuclear strategy. What effect do these developments have on North Korea's nuclear threshold, or nuclear red line? Drawing on Kim Tae-hyun's (2016) framework of objective and subjective nuclear thresholds together with the recent body of research on North Korea's variant of CNI, this study analyzes how new technology-based conventional forces and new discourse directed at South Korea affect both the material and strategic conditions that make actual nuclear use possible (the objective threshold) and the psychological and cognitive conditions under which an adversary perceives the possibility of nuclear use (the subjective threshold). The analysis yields three findings. First, North Korea's objective and subjective nuclear thresholds are, on the whole, trending lower. Second, however, this shift is not uniform: rather than consistently signaling a lowered threshold for nuclear use, North Korea pursues a dual strategy, maintaining conditional and defensive ambiguity depending on the situation and the adversary involved. Third, as a result, even as the threshold for nuclear use is lowering, the actual conditions for nuclear use are becoming more ambiguous, heightening the risk of miscalculation and unintended escalation in a crisis. Accordingly, this study demonstrates that North Korea's nuclear threshold is not simply the product of expanding nuclear capability, but the outcome of a complex interaction among nuclear and conventional forces, emerging technologies, and political discourse, and proposes corresponding directions for deterrence and crisis management by South Korea and the United States. The paper proceeds as follows. Section 2 reviews the existing literature and the analytical framework. Sections 3 and 4 analyze changes in the objective and subjective nuclear thresholds, respectively. Section 5 draws on this analysis to present the study's policy implications.

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Bee Yun Jo｜September​ 30, 2026