(jungsupkim@sejong.org)

Senior Research Fellow,

○ New tactical guided weapons (KN-23, 24, etc.) are evaluated as forces of dual use that are capable of mounting both conventional and nuclear warheads with improved surprise attack capability, accuracy, and interception avoidance capability

○ Ultra-large ICBM (Hwasong-16) is estimated to have a multi-warhead carrying capacity (2-3 nuclear warheads) within a range (13,000 km or more) that can hit the eastern U.S.

○ New SLBMs (Pukguksong-3/4/5) and mid-sized submarines (3,000 tons) are expected to be able to hit Guam from North Korea's East Sea, and the development of nuclear submarines is expected to take a considerable time due to technical difficulties such as the construction of small nuclear reactors

○Atmospheric re-entry and MIRV technology required to strike the U.S. mainland have not reached the reliable level yet

■ The doctrine of North Korea's nuclear deterrence implied by new tactical·strategic weapons

○ The new weapon makes it clear once again that North Korea is pursuing 'minimum deterrence' against the U.S. mainland

○ There is a focus on maximizing the viability and retaliatory capability of nuclear weapons (SLBM, mobile ICBM, multi-warheads, etc.) in order to secure 'second strike capability' against large U.S. cities

○The development of new tactical weapons is part of the 'deterrence by denial' strategy that blocks the deployment of U.S. reinforcements by securing tactical nuclear attack capabilities on the Korean Peninsula and Japan

○ North Korea's nuclear readiness implies that it is not just 'assured retaliation' but also 'asymmetric escalation' where early use of tactical nuclear weapons is inevitable (this is similar to Pakistan's nuclear program, which seeks to make up for the inferiority of conventional forces with tactical nuclear weapons)

○ By combining retaliation capabilities against the U.S. mainland (assured retaliation) and rejecting capabilities of South Korea, Japan, and the West Pacific region (asymmetric escalation), maximum deterrence effect is pursued

■ Implications for the South Korea-U.S. nuclear deterrence strategy

○ If North Korea's nuclear capability approaches hitting the U.S. mainland, the reliability of extended deterrence will be raised, yet excessive pessimism should be avoided

○ The doctrine of North Korea's nuclear deterrence using tactical nuclear weapons has lost much of its meaning due to the U.S. low-power nuclear weapons development program promoted through the NPR in 2018

○ Some raise the need for NATO-style shared nuclear control, but in order to improve the reliability of extended deterrence, it is desirable to continue to deepen policy-level discussions on conditions, procedures, and decision-making of the use of nuclear weapons on the Korean Peninsula

○ Considering the limitations of the cost-effectiveness of missile defense, it is necessary to adjust the priority between interception (deterrence by denial) and strike (deterrence by punishment) and pursue the optimal combination

○ It should be noted that the 'strategic target strike,' which includes the concept of a preemptive strike in the South Korean military's 「nuclear·WMD response system, 」 has a dangerous and unstable effect (the pressure of use them or lose them) that further lowers the threshold of nuclear use along with the doctrine of North Korea's tactical nuclear use