Unprecedented Nuclear Strikes of the Invincible Army: A Realistic Assessment of North Korea's Operational Nuclear Capability

IntroductionAlthough North Korea's KCNA news often threatens to launch "unprecedented nuclear strikes," in reality, the North Korean nuclear program has limited offensive capability.1 Just how limited is a matter of dispute between well-informed observers and analysts. South Korea's defense minister, Kim Kwan-j in, for example noted recently that it was "possible" that North Korea had miniaturized a nuclear warhead as there had been, in his opinion, "enough time for them to have succeeded in miniaturization."2 He based his statement on how long it took other states to miniaturize a nuclear warhead, not on an assessment of North Korea's actual nuclear capability. Additionally, even if North Korea has miniaturized a nuclear warhead, the DPRK lacks an effective delivery mechanism and therefore has a limited ability to offensively use nuclear weapons.In our own assessment of North Korea's nuclear capability we found that the North is capable of operationally using nuclear weapons, but its options for a nuclear strike are severely constrained. We concluded that the only credible use of the DPRK's nuclear arsenal would be to detonate a bomb within North Korea itself to slow down or to stop an invasion in the context of an all-out war. Aside from this nuclear-use scenario, conventional weapons predominate in realistic evaluations of deterrence and war-fighting in the Korean Peninsula.North Korean Declaratory Nuclear PostureThe stated purpose of the North Korean nuclear program has changed over the last decade.3 North Korean statements that once described the nuclear program as a tool to secure the state against outside aggression now describe it as a stabilizing force in the region.During and after the collapse of the Agreed Framework in 2002, KCNA statements described the nuclear program as a substitute for a security guarantee from the United States. If North Korea's security concerns were addressed, they argued, there would be no need for the nuclear program. An October 2002 statement is particularly telling: "The settlement of all problems with the DPRK, a small country, should be based on removing any threat to its sovereignty and right to existence. There may be negotiations or the use of deterrent force to be consistent with this basis, but the DPRK wants the former, as far as possible."4By 2005 this language had changed. North Korea declared itself to be in possession of nuclear weapons and began to depict its nuclear program as a regional stabilizer which prevented war by countering the U.S. nuclear threat to the region.5 KCNA statements even suggested that North Korea's nuclear program benefited South Korea by raising a nuclear umbrella over the entire Korean Peninsula!6By 2010 North Korea had not only openly threatened to use its nuclear weapons for the first time, saying that "those who seek to bring down the system in the DPRK, whether they play a main role or a passive role, will fall victim to the unprecedented nuclear strikes of the invincible army,"7 but also made the first real declaratory statement of its nuclear posture in response to the U.S. nuclear posture review:The mission of the nuclear forces of the DPRK is to deter and repel aggression and attack against the country and the nation until the denuclearization of the Korean Peninsula and the world is realized. The DPRK is invariably maintaining the pol- icy not to use nuclear weapons against non-nuclear states or threaten them with nuclear weapons as long as they do not join the act of invading or attacking us in conspiracy with nuclear weapons states.8Although these statements should be taken very seriously, particularly by South Korea and Japan who are implicated in both via their alliance with the United States, we should not assume that North Korea has the operational military capability to back up this declaratory posture and the stated nuclear threats.North Korean Technical Nuclear CapacityWhen it comes to nuclear threats against the United States, South Korea, and Japan, North Korea vastly overstates its ability to strike. …