South Korea’s Nuclear Temptation

In the last three months, North Korea has tested two rocket technologies and a nuclear weapon. After many previous such tests, it is now increasingly apparent that North Korea has no intention of slowing its buildup, much less denuclearizing. While there are some actions which might help mitigate this buildup – missile defense, further sanctions, coordinated pressure on China, decentralization and civil defense in South Korea – the temptation for South Korea to build its own nuclear weapons is growing. Although this is South Korea’s sovereign right, I will argue here that Southern nuclearization is unnecessary. In any contingency where North Korea actually used a nuclear weapon, the entire world, including China and Russia, would immediately assent to the regime’s elimination. South Korea and the United States would invade North Korea forthwith and eventually win. Therefore, any nuclear strike on North Korea by the South (or the U.S.) would suddenly become unified (South) Korea’s responsibility to clean up.

The Strategic Situation

In January, North Korea tested a fourth nuclear device; in February, it launched a multi-stage rocket. It claimed this was to place a satellite in orbit, but the nearly universal response from outside analysts is that this was yet another step in the development of ballistic missile technology. North Korea appears intent on developing an intercontinental ballistic missile (ICBM). Already, North Korea can probably strike regional capitals with a nuclear weapon – Seoul, Tokyo and Beijing (yes, Beijing – the nuclear program serves to reinforce Pyongyang’s autonomy against its patron). An ICBM would open up North America and Australia to the Northern threat.

And it gets worse. North Korea declared that its January nuclear test was of a hydrogen bomb. This is generally considered to be ruse, but it does suggest that North Korea intends to build toward an H-bomb. The United States and Soviet Union moved quickly from their first crude fission weapons to thermonuclear weapons more powerful by an order of magnitude. It is not unreasonable to guess than Pyongyang will achieve this as well by the early 2020s. North Korea has also experimented with submarine-launched ballistic missiles. This would add substantial flexibility and range. Its latest sub test was in December 2015.

The upshot of all this is that the South Korean government has all but accepted that North Korea is now a major strategic, if not existential, threat. In her speech to the South Korean parliament on February 16, 2016, President Park Guen-hye basically admitted that the Sunshine policy, trustpolitik, and other engagement methods have inadvertently helped Northern nuclearization: “It has now become indisputably clear that the existing approach and good intentions will by no means work in countering the North Korean regime's determination to develop nuclear weapons, but will only lead to the enhancement of the North's nuclear capabilities, with catastrophic implications for the Korean Peninsula.”

Unsurprisingly, South Korean opinion is drifting toward its own, counter-nuclearization, and prominent South Korean officials are calling for this as well. While it is of course, South Korea’s sovereign right to make this choice – without American, Chinese, or Japanese meddling – I believe it is ultimately unnecessary.

Nuking North Korea, Even in War, Would Be a Mistake

South Korea does not need nuclear weapons, because it will never use them against North Korea. Because of their huge destructive power and the strong global norms against their use, the only possible contingency where South Korea would nuclear-strike North Korea is in response to an earlier Northern nuclear strike on it. But in that contingency, the Koreas would be at war, and South Korea (with U.S. and Japanese assistance) would be invading North Korea anyway. South Korea would almost certainly win that war, in which case Seoul would then be responsible for the nuclear cleanup of the blast zone(s) in the north which it had just created a few weeks earlier.

As bizarre as it sounds, it makes sense not to nuke North Korea, even if it nukes South Korea, because South Korea’s goals in such a scenario would be irredentist, not defensive. Because South Korea would also be seeking to absorb North Korea in any scenario in which it would consider nuking North Korea, nuking North Korea immediately becomes counterproductive. A Northern nuclear strike would immediately ignite an all-out war in which the South would seek to conquer North Korea once and for all. Because we expect South Korea to win that war, the victorious South would then be stuck with a postwar irradiated environment in both the southern and northern ends of the peninsula. Better a post-nuclear environment with fewer blast zones than many, even if it awkwardly means those blast zones are in the south only.

The only exception to this would be if South Korea and its allies were unexpectedly losing the war with the North. If North Korea were to launch devastating first strikes on the South, and possibly Japan and the U.S., coupled with an invasion of the South, such an extreme circumstance might justify using tactical nuclear weapons against the North Korean People’s Army, much as NATO reserved the right of first use of battlefield nuclear weapons to hedge East Bloc numeric superiority during the Cold War. But this circumstance is highly unlikely, and the United States could still provide the relevant weaponry for such a contingency. Further, even this dire scenario does not require strategic, “counter-value” (targeting civilians and infrastructure) strikes on Northern cities. These would create so much devastation in the North, that those blast zones would be huge additional burdens on postwar, post-nuclear, unified Korea. It is simply not worth the massive postwar costs to use large nuclear weapons in an area that will be shortly occupied permanently.

This irredentism is the difference between the inter-Korean nuclear competition and that between the U.S. and Soviet Union or India and Pakistan. Any contingency in which North Korea used nuclear weapons (against South Korea, the U.S., Japan, even China) would immediately unite global public opinion behind the final destruction of the regime. Even China would likely agree that a North Korea dangerous enough to use nuclear weapons should be destroyed. One could envision China cooperating with South Korea and the U.S. in the final invasion of the North. Any blast zones in the north would then become the awful inheritance of the newly unified Korea.

By contrast, the U.S., Soviet Union, India, and Pakistan had/have no serious irredentist/imperialist claims. These four players’ goals against each other are defensive, so nuking the other side, if it came to that, makes sense. The nuclear devastation created would be someone else’s to clean up. South Korea does not have that luxury. A post-nuclear environment of fewer blast-zones is ideal, creating the counter-intuitive, frustrating conclusion that we should not nuke North Korea even if it nukes us.

Costs to Southern Nuclearization

If the benefits of Southern nuclearization evaporate on inspection, there are also costs and hindrances – legal, political, and moral. Legally, South Korea is prohibited from building nuclear weapons, because it is a signatory of the Non-Proliferation Treaty (NPT). This is only a formal hindrance of course. Seoul could provide notice of its departure and withdraw on schedule, as permitted by the treaty. Like Japan, South Korea already has the technology to develop a bomb rather quickly. Were it to withdraw from the NPT, it could move rapidly, but this would provoke political tensions with its alliance partners, and generate moral or “audience costs.”

The United States has generally discouraged nuclear weaponization among its allies, in East Asia and elsewhere. The U.S. provides “extended deterrence” to many states, including South Korea and Japan. And the American defense commitment to those two countries is about as credible as possible. The U.S. government has repeated again and again in joint statements its willingness to assist them. While there is American public reticence about another major war in the world, Northern nuclear use would be such a huge shock, it is hard to imagine U.S. public opinion not supporting a post-nuclear South Korean war effort. Given this credible and nuclear-if-necessary American commitment, Southern nuclearization generates alliance tensions that probably are not worth it (although this is and must remain a South Korean sovereign decision).

Finally, there are less obvious audience costs. Right now, South Korea enjoys the moral high ground in the standoff with North Korea. It has responded with restraint and caution to Northern provocations for many years. It kept open the Kaesong Industrial Complex (KIC) for more than a decade, sending North Korea $500 million or more, coupled with millions more in aid since the 1990s. It has not responded to North Korean missile and nuclear provocations in kind. The outcome of this restraint is nearly unified global opinion that North Korea is to blame for regional tensions. At the UN, Northern nuclearization has isolated Pyongyang badly, provoked sanctions, and raised the possibility of human rights prosecution. Most importantly, outrageous Northern behavior generates intense, unwanted negative publicity for China and provokes debate there over sustaining its client. Southern nuclearization would squander these advantages. North Korea, China, and Russia would be quick to assert that Northern nuclear weapons were simply a quid pro quo. A “moral equivalence,” pox-on-both-their-houses interpretation would be reduce global public pressure, on China especially.

Other Responses

So if Southern nuclearization yields little beyond psychological gratification, what is to be done after these latest tests? Maddeningly, more of the same:

1. Missile Defense.The most obvious response is substantially thickening or “layering” South Korean missile defense. The South Korean debate on the installation of the American Terminal High Altitude Area Defense (THAAD) system should now be all but over. It is blindingly obvious that South Korea needs THAAD (plus more Patriot-3s), and soon.

2. More Sanctions. Contrary to popular perception, North Korea is not in fact that heavily sanctioned. South Korea took the first step by (finally) closing KIC. New sanctions at the UN, as well as unilateral sanctions by the U.S. and Japan are coming. (Where is the EU?). To be sure, China does not really enforce these, and North Korea can raise hard currency in other, often illicit ways. But these new sanctions increasingly target Northern finances, which it likely uses in the global nuclear proliferation black market, like the old AQ Khan network. And the elimination of legitimate monies through KIC should make it harder to wash Pyongyang’s illicit money, opening up banks doing business with North Korea to clearer sanctioning.

3. Keep Pushing China. To be sure, the China route to North Korean change has proven a great disappointment. But given how much China does to keep Pyongyang afloat, I see little choice but to keep hammering away. China is sensitive to audience costs or the loss of face. If the democracies can continue to globally embarrass China with North Korean misbehavior, if it appears to Beijing decision-makers that support for North Korea is isolating China and costing it even the good will of South Korea (its one hope for a “weak link” among U.S. regional partners), Beijing may eventually come around.

4. Prepare to Ride-Out a Northern Nuclear Strike. Finally, South Korea should start “thinking about the unthinkable.” In the eight years I have lived in South Korea, I have always been struck by how blasé South Koreans are about the Northern nuclear and conventional missile threat. There are monthly air-raid drills, but these are so pro-forma now, that people just stand around waiting for the 15 minutes to end. I have never met a student or friend who knew where bomb shelters were or what do in the case of missile attack. To be sure, civil defense is challenging (the U.S. all but gave up on it during the Cold War), but there obvious steps that South Korea could take to “harden” itself to ride out, at least somewhat, a Northern missile attack. The most obvious would be a long-term effort to decentralize South Korea so that its crowded urban centers are a less appealing target. The Seoul-Incheon-Gyeonggi corridor particularly is hugely vulnerable, as it begins just 30 miles from the demilitarized zone, contains over 50 percent of the population, and is the nation’s political and economic center of gravity. It is glaring, decades-old failure of South Korea planning that no effort was made to prevent mass agglomeration right on the border.

Seventy percent of South Korea’s population lives on just thirty percent of its landmass, which concentration makes the threat of nuclear strikes that much more destabilizing. Decentralization, such as moving the capital far from the front line, would surely cost money and be inconvenient, but the national security case for it is now existential. So dense and few are South Korean cities that only a few Northern nuclear missiles need to get through to dramatically destabilize society and throw the Republic of Korea’s constitutional survival into doubt. More and less densely populated cities – yes, even if it costs a lot of money – is the best way to enhance ROK long-term survivability against these state- and society-breaking weapons.