Kim Jong Un Nuclear Submarine Construction: A Tit-for-Tat Escalation

An 8,700-ton nuclear giant is taking shape in North Korea. On December 25, 2025, North Korean leader Kim Jong Un inspected the construction of a new nuclear-powered strategic guided missile submarine, as reported by the state-controlled KCNA. The visit, notably accompanied by his daughter Kim Ju Ae, underscores Pyongyang's commitment to radical naval modernization.

Strategic Impact of Kim Jong Un Nuclear Submarine Construction

The inspection is widely seen as a direct response to South Korea's success in securing U.S. approval for its own nuclear-powered submarine project. In October, President Lee Jae-myung convinced President Trump to greenlight Seoul's bid for nuclear propulsion. Kim Jong Un labeled this move an "offensive act" and emphasized that North Korea's own nuclear development is an "indispensable option" to counter regional instability.

Escalating Tensions and the 'Power for Power' Doctrine

Pyongyang's stance has become increasingly hawkish following the 2019 Hanoi summit failure. Strengthened ties with Russia's Vladimir Putin and the growing strategic competition in East Asia have provided Kim with more leverage. While President Lee has sought to renew inter-Korean dialogue since assuming office in June 2025, North Korea's recent actions suggest it's more interested in direct negotiations with Trump than responding to Seoul's gestures.