This article analyses the misperceptions, confirmation bias and groupthink exhibited by South Korea’s progressive presidents regarding North Korea’s nuclear armament and the prospects for denuclearisation. Historically, progressive administrations have characterised North Korea’s nuclear programme as fundamentally defensive—intended for regime survival—and as a negotiable issue that could be resolved through voluntary disarmament. These perceptions have persisted to the present, reinforced by entrenched confirmation bias and groupthink. An in-depth examination of the Moon Jae-in administration demonstrates that the misperceptions, confirmation bias and groupthink held by the president and his advisors regarding Pyongyang’s willingness to denuclearise led to an overemphasis on negotiations. This approach ultimately provided North Korea with the time necessary to consolidate its nuclear arsenal and undermine the credibility of the US nuclear umbrella. Consequently, South Korea’s progressive political leaders must transcend these cognitive biases and prioritise the development of robust deterrence and defence measures to protect the South Korean public from the North Korean nuclear threat.
Hwee‐rhak Park (Sun,) studied this question.