Seoul is only 30 miles from the DMZ.

Seoul is only 30 miles from the DMZ.

For over twenty years, it has been evident that North Korea lacked the capacity to successfully conquer the Korean Peninsula through military invasion. Economic stagnation after (among other things) the fall of the USSR led to military deterioration, and it appeared that North Korea’s giant military was a powerful deterrent to invasion and an instrument of internal control, but nothing more. In the present day, South Korea has twice the population and forty times the economic power of the North, and by most metrics its military forces far outclass those of the North. However, one contingency seems to be missing from the discussion: what if the North Koreans grew desperate enough to attempt to conquer only the portions of South Korea closest to them, since after all, those are the most valuable parts?

According to at least one North Korean defector, the North Korean military intended for at least some of its tunnels, dug under the Demilitarized Zone (DMZ), to connect with the Seoul subway system. To an extent, this is a bit comical, evoking cartoon slapstick (picture an invading force storming into the subway, only to be blindsided by a speeding train) or perhaps the members of Spinal Tap, wandering about backstage, unable to find their audience (this apparently happened to KISS once). With that said, it illustrates a stark reality of Korean geography. The Seoul area lies only about thirty miles from the Demilitarized Zone. This is often mentioned in the context of Seoul’s vulnerability to massed North Korean artillery, missiles, and rockets. As the tunnels demonstrate, it is at least theoretically possible for large numbers of North Korean soldiers to reach Seoul’s outskirts on foot, and initially undetected.

The Seoul metropolitan area (including the port city of Incheon, site of General MacArthur’s famous landing) is surrounded by a densely populated province, Geyonggi-do. This province, and especially the cities it surrounds, contains nearly half of the country’s population and is overwhelmingly the center of South Korea’s commerce, finance, and industry. Immediately to the east lies Gangwon-do, a sparsely populated rural province, noted for its abundant agricultural land. Both of these prizes lie immediately to the south of the DMZ. Thus, the scenario: if North Korea continues to deteriorate (and there is no guarantee that this will happen, but it is likely), might Kim Jong Un’s government decide that the tiny chance of success of seizing large portions of the peninsula’s most valuable territories beats the sure thing that their regime will crumble beneath them in their own lifetimes?

The plan might go something like this: the North spends several months gradually moving substantial forces close to the DMZ, and stockpiling supplies, including perhaps fuel synthesized from coal (if the North Koreans cannot do this, the Chinese can). When the attack comes, North Korea’s massed artillery and missile batteries will open fire not on Seoul’s residential areas, but on every known South Korean military base in the area, plus a few farther afield. Bombers and ground-attack aircraft (including many scores of obsolete fighters) will launch massed airstrikes on military targets, while fighters attempt to distract the South Korean air force (they cannot defeat them) from defending their air space and retaliating. Shortly thereafter, armor and infantry of the Korean People’s Army will surge southward through the DMZ, attempting to smash through South Korean (and possibly American!) military units and proceed south.

Crucially, the North Koreans have attempted to compensate for their decaying military capabilities by reinventing huge parts of their military as asymmetric-warfare specialists. The North Koreans are thought to have about 200,000 special-operations troops (with better food, equipment, and training than most of their comrades, with a particular emphasis on indoctrination), along with “several” conventional army divisions repurposed as light-infantry units. Besides simply sneaking through the DMZ, these soldiers can be delivered en masse from helicopters, transport planes such as the AN-2, hovercraft, submarines, small boats, and any undiscovered tunnels. They are known to possess copies of South Korean uniforms and equipment, and are trained and equipped to sow chaos and disorder. Surely they are well-aware of the efficacy of roadside bombs.

The Kim regime may be hoping that, once their troops penetrate into built-up urban areas, South Korea’s massive technological advantages and air superiority will be less relevant. The North Koreans are notably known to be involved in cyber-warfare and GPS jamming, in attempting to level the playing field. Similarly, Pyongyang might count on both the United States and the remnants of South Korea being in no financial, political, and/or military position to mount a counter-attack, partially due to fear of provoking the Chinese, and they may have a point.

So would it work? Almost certainly not, unless the North Koreans have been able to upgrade their command and control capabilities to the degree necessary to pull off such a coordinated operation with any degree of surprise. If they lose the momentum, they would be routed by superior South Korean forces, and the ensuing conflict would instead lead to the fall of the government in Pyongyang, not Seoul. Even if the initial phases of the campaign went according to plan, the loyalty of the North Korean forces might easily crumble upon coming into close personal contact with the glitz and vibrancy of Seoul and the lush bounty of Gangwon-do. Before (or as) the disparities between the two countries reached a tipping point, this strategy might have been viable; now, it might just enable defection on a massive, perhaps terminal scale. Even with a party-line blaming their problems on foreign sanctions, both military personnel and civilians defect from North Korea on a regular basis as it is. On top of that, could the North Koreans control such a large and restive civilian population?

Might it still happen? Yes, for reasons outlined above. Pyongyang might prefer to take a chance, rather than succumb to a pathetic certainty. Also, the scenario might become more likely if the North Koreans, from their perspective, felt pushed to the wall by the escalating saber-rattling between both sides, regardless of who started it. The phenomenon of “groupthink” (which does not mean thinking or acting as a group, rather it essentially refers to teamwork gone wrong) is notorious for occurring in tense, cohesive, homogenous, insular groups. Those characteristics do seem to fit the government in Pyongyang.

It is wrong (as usual) to dismiss Kim and his cohorts as irrational or crazy, but it is highly possible they might be delusional enough, due to ignorance or pathologies like groupthink, to make a very bad decision. The South Koreans (and the Americans, who have no direct national interest in the matter) should not make it any more likely for them to do so. Rather than brinksmanship around the topic of nuclear weapons, they should take care not to leave Pyongyang with only one drastic option: an enormous “limited” war.

Scott Ryan Charney received an M.A. in U.S. Foreign Policy from American University.