Recent weeks have seen growing alarm over North Korea’s nuclear program. This month, numerous senior U.S. military officials said that Washington believes North Korea has the ability to strike the western United States with a nuclear-tipped KN-08 intercontinental ballistic missile. “Our assessment is that they have the ability to put a nuclear weapon on a KN-08 and shoot it at the homeland. We assess that it’s operational today,” William Gortney, commander of the North American Aerospace Defense Command (NORAD) told reporters.
The Wall Street Journal reported that Chinese experts believe Pyongyang has already amassed twenty nuclear warheads, and could double that number within a year. That report came on the heels of a widely discussed report by the U.S.-Korea Institute at the Johns Hopkins School of Advanced International Studies (SAIS), which assessed that North Korea could drastically expand the size of its nuclear arsenal over the next five years.
Specifically, in its most dire forecast, the SAIS report suggested that North Korea could expand its nuclear arsenal from 10-16 nuclear warheads today, to as many as 100 warheads by 2020. The report’s mid-range forecast was that North Korea will have 50 nuclear warheads in five years’ time, while its low-end estimate is that Pyongyang will have just 20 bombs in 2020.
These revelations have greatly unnerved regional analysts. Indeed, in a recent article on The Diplomat, Robert Kelly argued that if North Korea’s nuclear arsenal keeps expanding, South Korean leaders may need to consider a preemptive strike to destroy Pyongyang’s strategic weapons.
The concerns are largely overblown, however. There is little reason to think that North Korea will greatly expand the size of its nuclear arsenal in the near future. But even if Pyongyang were to do so, South Korea would be foolish to try a preemptive strike.
Slow and Steady
Although North Korea’s growing uranium-enrichment capabilities enhances its ability to produce more nuclear warheads, there are compelling reasons to think North Korea will not drastically increase the size of its arsenal in the coming years.
To begin with, such a rapid buildup would be completely at odds with the history of North Korea’s nuclear program, which has proceeded at a snail’s pace. North Korea began seeking nuclear weapons at least as early as 1980, but didn’t test its first device until 2006 – some 26 years later. Nothing has changed in the nine years since. As noted above, North Korea likely only has 10 nuclear warheads in its arsenal, and 20 at most. Since that first test, then, it has been producing nuclear weapons at a pace of no more than 2.75 bombs a year, and possibly as few as 1.5 annually (factoring in the two warheads used in the 2009 and 2013 tests) To suggest that North Korea may suddenly start building twenty warheads of year ignores the entire history of Pyongyang’s nuclear program.
Moreover, despite its increased enrichment capabilities, a number of factors are likely to constrain North Korea’s nuclear buildup in the near future. For one thing, North Korea remains an appallingly poor country, and this is the greatest threat to the regime. Indeed, Kim Jong-un’s overarching governing agenda (called the “byungjin line”) is built on the simultaneous development of nuclear weapons and the economy.
The latter is hardly an afterthought. While the North Korean government has adamantly refused to surrender its nuclear stockpile in exchange for economic incentives, Kim Jong-un has advanced bold economic reforms (by North Korea standards, at least) during his short time in power. This includes more aggressively seeking out international investors and promoting tourism. His regime has also begun decentralizing farms and allowing individual farmers to keep more of their crops. Some have compared these agricultural reforms (called the “June 28 measure”) to the ones China adopted in 1987. The June 28 measure was soon deepened and expanded to apply to other industries under the “May 30 measure.” Perhaps most significantly, the North Korean government has been establishing special economic zones at a feverish pace, with no fewer than 19 new SEZs announced since 2013.
These reforms are already paying dividends. In recent years, the UN Food and Agricultural Organization (FAO) has assessed that North Korea’s food security is improving. Moreover, after years of annual contraction, since 2011 the Bank of Korea (South Korea’s central bank) has reported that North Korea’s economy has begun growing. This has forecast modest growth rates for North Korea in the coming years, after years where North Korea’s economy contracted annually. This economic growth appears to be accelerating; South Korea’s Hyundai Research Institute predicts that North Korea’s economy will grow by 7 percent in 2015.
All this suggests that Kim Jong-un sees improving the economy as crucial to shoring up his regime. In particular, he likely sees improving the livelihoods of the country’s elite as essential to staying in power. Indeed, the worsening economic situation was a central reason that Kim Jong-il was never able to achieve the popularity of North Korea’s founder and eternal president, Kim il-Sung. Kim Jong-un has tried to emulate Kim il-Sung since he first entered the public spotlight, and improving North Korea’s economy is one aspect of this.
Kim Jong-un’s need to improve the economy constrains his ability to rapidly expand the size of North Korea’s nuclear arsenal. To begin with, as the SAIS report indicates, a rapid expansion of North Korea’s nuclear arsenal will require frequent nuclear tests. These tests, however, invite swift international retribution, including from North Korea’s primary patron, China. Frequent nuclear tests would also cripple Kim Jong-un’s efforts to improve relations with Russia.
In addition, rapidly expanding North Korea’s nuclear arsenal would be prohibitively expensive. In fact, it is not only expensive to build the actual nuclear warheads, but also to maintain a nuclear enterprise. The costs of this latter, of course, increase significantly the larger a country’s nuclear arsenal becomes. In 2011, for example, Global Zero estimates that North Korea spent about $700 million on its nuclear program. Meanwhile, Pakistan – which is believed to have between 90-110 nuclear warheads – is believed to spend at least $2.2 billion on its nuclear arsenal annually, and possibly as much as $2.5 billion. This would be a huge chunk of North Korea’s overall military spending, which is around $9 billion a year, according to South Korea’s state-run Korean Institute of Defense Analyses.
As this suggests, besides the economic factors, there are important strategic constraints on North Korea’s ability to rapidly expand the size of its nuclear arsenal. First among these is the tradeoff between its nuclear weapons program and its conventional military capabilities. That is, as in other nuclear countries, expanding North Korea’s nuclear program would come at the expense of its conventional capabilities.
This is important because North Korea maintains the fourth largest military in the world. Moreover, North Korea appears to have undertaken something of a military modernization program, particularly in the realm of naval warfare. As Joseph S. Bermudez Jr. notes, “Since the early 2000s the Korean People’s Navy has undertaken both a small-scale shipbuilding program and a series of upgrades to a number of its existing vessels and weapon systems.” Although this began under Kim Jong-il, Bermudez believes it has accelerated since Kim Jong-un assumed power. It would make little sense to begin these modernization programs if nuclear weapons development were going to consume much of the defense budget in the years ahead.
There are other strategic constraints on North Korea’s ability to rapidly expand the size of its nuclear arsenal as well. Most notably, for the foreseeable future, North Korea is almost certainly going to be more concerned with making qualitative improvements to its nuclear weapons arsenal, rather than simply trying to build up the number of nuclear weapons it possesses.
Indeed, despite common belief, as well as the country’s own constant boasts to the contrary, North Korea is not currently a nuclear weapons state. At best, North Korea’s nuclear enterprise has demonstrated that, if given weeks to prepare, it can probably conduct a nuclear explosion. Even this may be an overly generous interpretation. Before its first nuclear test in October 2006, for example, North Korea reportedly informed China that it would explode a four-kiloton nuclear device, was itself shockingly small. By way of comparison, CNN noted shortly after that India and Pakistan’s 1998 nuclear tests registered around 15-kiloton yields, and America’s first nuclear test in 1945 produced a 20-kiloton yield. North Korea nonetheless failed to achieve even this relatively modest goal as the resulting nuclear denotation was estimated to have produced just a 0.48-kiloton yield.
North Korea’s second nuclear test was only slightly more successful, producing a 2.35 kt yield, according to an estimate later published in the Bulletin of the Seismological Society of America. Even this was a matter of some dispute, however. A Congressional Research Service report later noted that, “Unlike its first test, in 2006, there is no public record that the second one released radioactive materials indicative of a nuclear explosion.” The U.S. Intelligence Community would only say that North Korea “probably conducted” a nuclear test. After assessing the different possibilities, Jeffrey Park, a Yale geology professor, said the most likely explanation was that “North Korea tried and failed to get a simple plutonium bomb to detonate correctly.”
North Korea’s third nuclear test in 2013 was by far the most successful, producing a yield of somewhere between 7-15 kt, with perhaps the best estimate pegging the yield at 12.2 kt. Still, this was at best equal to India and Pakistan’s 1998 nuclear tests, and almost certainly below it.
In any case, none of this suggests that North Korea is a nuclear weapons state. As noted above, these tests occurred only after weeks of careful and unimpeded preparations, which are hardly the conditions North Korea could realistically expect during wartime.
In fact, Pyongyang faces a number of remaining obstacles before it can boast of having deployable nuclear weapons. Perhaps the most pressing (and certainly the most discussed) is miniaturizing a nuclear warhead so it can be placed on one of North Korea’s missiles. Although the U.S. said earlier this month it is operating under the assumption that Pyongyang has acquired this capability, this assessment is based on an abundance of caution. It is widely doubted by experts, and North Korea has notably has not demonstrated this capability.
Miniaturizing a nuclear warhead isn’t the only obstacle must overcome. As Jeffrey Lewis (who believes North Korea probably has all the requisite capabilities) noted in a recent article, there are at least two other obstacles Pyongyang must overcome. First, it has to design a nuclear warhead that can withstand the “shock, vibration and temperature change” it will encounter in flight. Second, it must design reentry vehicles that can withstand the scolding temperatures it will encounter when it reenters the atmosphere. This is a challenge that other countries like China struggled to overcome.
Even once these obstacles are surmounted, there are a few additional challenges North Korea will have to overcome. The first, of course, is achieving technical reliability for both its warheads and missiles. Even if North Korea is able to demonstrate all the necessary technological achievements in a single test, Pyongyang will need to ensure it can replicate this success on a reliable basis. If the past is any guide, North Korea is likely to struggle immensely with this as well. In fact, a recent widely quoted assessment noted, “The challenges Pyongyang faces in developing new delivery systems over the next five years and beyond are likely to be greater than those encountered in its nuclear program.”
Second, even after North Korea weaponizes its nuclear capabilities, it will need to operationalize them, which “refers to command and control mechanisms, coordination procedures between scientific and military agencies, and training protocols in the military to deploy and explode weapons.” As Gaurav Kampani, a non-resident fellow at The Atlantic Council, noted in a path-breaking article on the subject, “If the weapon systems constitute the hardware, operational routines make up the software that enables use of weapons during war.” North Korea is likely to struggle with this aspect of becoming a nuclear weapon state. As Kampani notes, the gap between weaponization and operationalization has increased dramatically in the modern atomic era. Whereas it took the P5 states (the United States, Russia, the United Kingdom, France and China) an average of four months to operationalize their nuclear weapons, it has taken the nuclear weapon states since an average of four years to do so.
It is these weaponization and operationalization challenges that are likely to consume the bulk of the North Korean nuclear enterprise’s attention in the coming years. After all, what’s the point of building a ton of warheads if you cannot use them?
Living With a Nuclear North Korea
At some point in the future, however, North Korea is likely to overcome these challenges and build a much larger nuclear weapon stockpile. This situation would not be catastrophic for South Korea, however, and – counter intuitively – may even be preferable to Pyongyang possessing a small nuclear arsenal.
As Robert Kelly noted in his article on The Diplomat, the superpower nuclear balance was least stable during the early Cold War when both sides lacked a second-strike capability. That is, they lacked the ability to absorb a surprise attack and retaliate with overwhelming nuclear force. This created both a temptation to launch a first strike against the enemy, as well as a “use-them-or-lose-them” mentality. The situation stabilized once the superpowers acquired a second-strike capability by expanding the size of their arsenals and diversifying their delivery systems. Among other things, second-strike capabilities reduce the chance of leaders making rash decisions based on incomplete or false information during crisis environments.
Kelly maintains, however, that North Korea will never acquire a second-strike capability primarily because of its small size and low technological base. As he puts it, “North Korea is too small to pursue the geographic dispersion strategies the Soviets tried, and too poor to build a reliable SLBM force or effective air defense.”
This is almost certainly false, however. The U.S is already operating on the assumption that North Korea has road-mobile ICBMs in the form of the KN-08, which can be moved around to elude the enemy. With a decently sized arsenal of road-mobile nuclear missiles, the United States and South Korea could not be confident that they would be able to successfully destroy all of North Korea’s nuclear weapons in a decapitation strike. Indeed, as NORAD commander Admiral Bill Gortney admitted of the KN-08: “It’s the relocatable target set that really impedes our ability to find, fix and finish the threat.” He added that this problem is compounded by America’s limited ISR capabilities in North Korea. America and South Korea’s confidence would be weaker still if North Korea acquires submarine-launched ballistic missiles, which it is believed to be pursuing.
There are a number of important differences between North Korea today and the situation the U.S. and Soviet Union faced during the Cold War. First, for the United States and Soviet Union, acquiring a second-strike capability meant building an arsenal that could survive a massive nuclear attack. Since South Korea doesn’t possess nuclear weapons, and the United States would be unlikely to use nuclear weapons except in retaliation, Pyongyang’s arsenal only needs to be able to survive a conventional attack. This significantly increases survivability. For example, despite being nearly six times as small as North Korea, Israel has been content with a small nuclear arsenal because it doesn’t have any nuclear-armed adversaries.
Second, since – as Kelly himself notes – the United States and Soviet Union were many times larger than North or South Korea, they needed many more nuclear missiles to survive a first strike in order to be able to launch a massive retaliation against the other. But, as Kelly points out, South Korea is many times smaller than the United States and Soviet Union, and the bulk of its population is concentrated in five cities. As a result, to achieve a second-strike capability, North Korean leaders would only need to be confident a few nuclear warheads would survive a first strike.
Kelly also argues that because of their country’s vulnerability to a small nuclear attack, South Korean leaders will launch a decapitation strike rather than allow North Korea to expand its arsenal. As he puts it: “Both the Soviet Union and the United States were so large, that only a massive first strike would have led to national collapse. In South Korea by contrast, nuking only about five large cities would likely be enough to push South Korea toward national-constitutional breakdown.”
There are at least two issues with this argument, however. First, given that only a few nuclear weapons would be necessary to threaten South Korea’s existence, it’s not clear why South Korean leaders can tolerate a small North Korean nuclear arsenal, but would launch a preventive attack to prevent it from expanding. Second, while many more nuclear weapons are necessary to pose an existential threat to large countries like the United States and Russia, both the U.S and Soviet Union did indeed build nuclear arsenals large enough to do just that. Thus, South Korean leaders would only have to live with the same balance of terror that characterized the Cold War.
It’s virtually certain that they will choose to do so rather than carrying out a preventive strike to destroy North Korea’s nuclear arsenal. Such an attack – which the U.S. would almost certainly refuse to participate in – would be incredibly risky.
To begin with, South Korea would likely fail to destroy North Korea’s entire nuclear arsenal. If only a few nuclear missiles survive the attack, North Korea would respond with the devastating nuclear strikes South Korea would have attacked to prevent. Even in the unlikely event that South Korea did successfully destroy all of North Korea’s nuclear weapons, Pyongyang’s artillery and other conventional weapons would ensure an enormous counterattack. This alone is enough to deter an attack.
In fact, as Kelly notes, the United States and South Korea have considered attacking North Korea in the past, such as during the 1994 nuclear crisis. They ultimately decided against doing so because of North Korea’s conventional military capabilities. As Don Oberdorfer notes in The Two Koreas, during the 1994 crisis “U.S. estimates were that in case of war, North Korea could pound Seoul with five thousand rounds of artillery within the first twelve hours, causing havoc, death, and destruction in the capital.” Oberdorfer also reported that American military planners believed a war with a non-nuclear North Korea in 1994 “would cost 52,000 U.S. military casualties, killed or wounded, and 490,000 South Korean military casualties,” to say nothing of civilians.
In other words, the only thing worse than living with a nuclear North Korea could be trying to disarm it through force. That was certainly the judgment of American leaders in the 1950s, when they briefly considered (and quickly rejected) a preventive strike to eliminate the Soviet Union’s nuclear arsenal before it was capable of threatening the United States directly. South Korean leaders will be forced to the same conclusion, however painful it may be.
Editor’s note: An earlier version of this article was published on The Diplomat on July 03, 2013.
Throughout the nuclear era, the conventional wisdom has been that when one state acquires nuclear weapons, its adversaries follow suit. As former Secretary of State George Shultz so eloquently put it: “proliferation begets proliferation.”
Although some of the earliest nuclear proliferation cases followed this pattern, it has been increasingly rare in recent decades. That’s likely because in the dawn of the atomic era, non-nuclear countries had little reason to believe nuclear adversaries would exercise unilateral restraint in using these awesome weapons. However, as the taboo against the first use of nuclear weapons has become more entrenched, non-nuclear states have become increasingly confident that they do not need their own arsenals to avoid becoming the victim of a nuclear attack.
Just because nuclear weapons are not needed to deter nuclear attacks does not mean these weapons have not proven to be strategically useful. In fact, nuclear weapons have proven incredibly effective at deterring large-scale conventional attacks. Not surprisingly, then, the primary security factor driving nuclear weapons proliferation today is conventional military weakness. This is likely to continue in the future, with profound consequences for which states do and don’t seek nuclear weapons.
Although the conventional military balance has become an increasingly important factor in states’ decisions to seek or forgo nuclear weapons in recent decades, it wasn’t completely negligible in earlier years. France’s pursuit of a nuclear weapon is a case in point. The conventional narrative says that France decided to build nuclear weapons because of Charles De Gaulle’s intense nationalism and lack of faith in America’s nuclear umbrella.
The archival record does not completely support this interpretation, however. To begin with, as Jacques Hymans finds from his careful review of the available documents, it was Mendes France, not De Gaulle, who made the first crucial decisions to pursue the bomb. The timing of President France’s decision is illuminating: he initiated the nuclear weapon program three days after NATO agreed to West Germany’s rearmament despite Paris’ objections.
President France’s rationale was straight forward. As Hymans explains, he believed that “French military power must remain at least one order of magnitude superior to Germany’s; thus, the fewer the restrictions on German conventional weapons, the greater the need for a French atomic force.” Given that France had lost three wars to Germany since 1870, including WWII where Berlin occupied France for years, his decision isn’t too hard to comprehend.
Israel’s decision to pursue the bomb was also motivated almost entirely by its perceived conventional inferiority vis-à-vis its Arab neighbors. Although these neighbors did not possess nuclear weapons, Israeli leaders in the 1950s and 1960s–most notably David Ben Gurion and Shimon Peres– were convinced the survival of the Jewish state depended on it possessing a large qualitative edge against its much larger Arab neighbors. This is not surprising given that Egypt alone is 55 times larger than Israel and, in 1967, had about eleven times its population. Israeli leaders therefore calculated that acquiring a nuclear weapon was the surest way to offset this inherent conventional imbalance, and thereby ensure the Jewish state’s survival.
As the nuclear taboo has become more entrenched over the decades, states have had less to fear from a neighbor acquiring an atomic weapon. Consequentially, conventional military power has surpassed enemy nuclear weapons in terms of its importance in driving nuclear proliferation.
North Korea illustrates this dynamic nicely. Although Pyongyang began its nuclear program during the Cold War, it only started making substantial progress in the late 1980s and early 1990s. Notably, this was when the nuclear threat it faced was declining as South Korea abandoned its nuclear ambitions in the 1970s and the U.S. withdrew its nuclear weapons from South Korea in 1991 (and had been drawing them down substantial in the decades before then).
By contrast, the 1980s and 1990s was also the time when the conventional military balance shifted decidedly away from North Korea’s favor. To begin with, in the late 1980s the Soviet Union began pursuing relations with South Korea, and North Korea ultimately lost its great power protectorate when the USSR collapsed in 1991 (before then its aid to North Korea began declining as Moscow’s economic woes mounted). The new Russian state quickly established diplomatic ties with South Korea, as did China in 1992. Furthermore, whereas North Korea boasted a larger economy than its southern neighbor through the mid-1970s, South Korea’s rapid economic ascendancy, combined with its inherent demographic advantage, ensured that its latent military capability increasingly outpaced Pyongyang’s. And that is without even accounting for Seoul’s military alliance with the United States.
Of course, the U.S. military is part of the equation on the Korean Peninsula, and its stunning victory in the first Gulf War left little doubt about its conventional dominance in the post-Cold War era. Undoubtedly, North Korean leaders watched the U.S. armed forces crush Saddam’s army with growing trepidation. This was ominous indeed for policymakers in Pyongyang, who rightly calculated that they couldn’t match America’s conventional military might. Consequently, they sought to negate its military superiority by acquiring the ultimate deterrent.
The Islamic Republic of Iran’s nuclear program has followed a similar trajectory. Although the initial decision to restart the Shah’s nuclear program was motivated almost entirely by Saddam Hussein’s nuclear and chemical weapons programs, Tehran only began making real progress on the nuclear front in the middle to late 1990s. Saddam Hussein can hardly explain this trajectory, given that his threat to Iran was significantly diminished following the first Gulf War, and it was eliminated entirely after 2003.
Iran’s nuclear program is better explained, then, by the growing threat Tehran saw from the United States. This began when America established a large military presence in the Persian Gulf following the First Gulf War. It only grew a few years later when, in July 1995, Washington decided to reactivate the 5th Fleet after a 45-year hiatus. Suddenly, America’s imposing naval forces were a constant presence in Iran’s coastal shore.
Further underscoring this danger to Iran, the following year President Bill Clinton signed the Iran and Libya Sanctions Act of 1996, confirming that President Akbar Hashemi Rafsanjani’s outreach to the U.S. had failed. The U.S. threat to Iran has only grown more precarious since 2003; not surprisingly, Iran’s nuclear program has made its greatest advances during this time.
The conventional military balance’s primacy in influencing horizontal nuclear proliferation is also evident from the states that have not chosen to go nuclear. For instance, no Northeast Asian country went nuclear following China or North Korea’s nuclear tests, nor did Israel’s nuclear arsenal cause a nuclear arms race in the Middle East.
Recognizing the centrality of conventional military power in driving nuclear decision-making helps us better anticipate future proliferation threats. For instance, if Iran acquires nuclear weapons, its neighbors will be unlikely to follow suit. Not only do these states lack the necessary technical capacity, but Iran lacks the ability to project conventional military power (Iran’s greatest threat to these countries comes from its support for proxy groups, which nuclear weapons are not effective at deterring.)
On the other hand, China’s growing conventional military power makes it likely that Eastern Asia will be the region where the most potent proliferation risks emanate from. Countries with territorial disputes with China—first and foremost, Japan— will have the strongest motivation to build the bomb. Unfortunately, for non-proliferation advocates, many of China’s neighbors—especially Japan but also South Korea— already have robust civilian nuclear programs. This breakout capability will only make it more tempting for policymakers to order a mad dash for the bomb.
Another potential area of concern is in Eastern Europe where Russia has already dismembered two states in the last decade as part of its bid to re-establish a sphere of influence. Moscow’s neighbors cannot possibly hope to compete with Russia’s conventional military power, and thus may look to the ultimate weapon to ensure their survival.
Editor’s note: This article was originally published in April 2013.
As I noted in passing last week, amid escalating tensions on the Korean Peninsula South Korea’s Defense Minister Kim Kwan-jin announced a new doctrine of “active deterrence,” which included Seoul taking preemptive action against North Korean missile and nuclear sites that it judged were being prepared for use.
This point seems obvious. No country is going to wait for nuclear weapons to actually reach their cities if they can avoid it.
Nevertheless, there were a couple of issues with last week’s announcement.
The first problem is that it occurred at all. By announcing that Seoul was considering a first strike against North Korea’s limited nuclear and/or missile capability, Defense Minister Kim gave North Korea every incentive to put these weapons on a higher state of alert. This doesn’t currently matter since Pyongyang can’t place a nuclear warhead on a missile, but it certainly will in the future, especially once North Korea has developed solid fuel missiles. Given that it’s taken weeks for North Korea to prepare for nuclear tests in the past— and that it likely has solid fuel short range missiles— Pyongyang is almost certain to have its forces in place to launch a nuclear or conventional attack at a moment’s notice in light of South Korea’s announcement.
Furthermore, the announcement also gave North Korean leaders a strong(er) reason to adopt a “use-it-or-lose-it” nuclear doctrine in which they launch nuclear warheads at the first sign of an attack. The reason is simple: Seoul has overtly adopted a strategy of trying to destroy Pyongyang’s nuclear arsenal and, given its limited size, could very well be successful unless North Korea can successfully launch its nuclear warheads before South Korean aircraft or missiles reach their intended targets. The same largely holds true for conventional weaponry, a successful preemptive attack by the ROK would almost certainly destroy a large chunk of Pyongyang’s deterrent forces. North Korea is determined to prevent this from occurring.
The danger of this should be readily apparent: in an atmosphere in which U.S. and ROK forces are engaged in extensive military drills—including over flights by nuclear-capable American bombers— one cannot dismiss the possibility that North Korea mistakes these drills for an in-process first strike against its nuclear and/or missile sites. Indeed, given that the North presumably lacks sophisticated early warning radar systems, even something like a defector crossing back into North Korea by sea or the U.S. and Japan flying intelligence drones over Northern air space could theoretically set off a jittery leadership in Pyongyang.
Finally, there is good reason to believe that South Korea intends to undertake this action unilaterally. Indeed, last February the ROK Chairman of the Joint Chiefs of Staff, General Jung Seung-jo, was quoted as saying:
“If [the North] shows a clear intent to use a nuclear weapon, it is better to get rid of it and go to war, rather than being attacked…. A pre-emptive attack against the North trying to use nuclear weapons does not require consultation with the United States and it is the right of self-defense.”
In theory the ROK forces exercising some autonomous capabilities could help stabilize the situation on the Korean Peninsula. If communicated carefully (i.e. ROK-only and designed to achieve limited objectives) an ROK-only operation could allow Seoul to respond to small North Korean provocations like the ones in 2010 without as much risk of the situation escalating to a full nuclear-scale war.
A preemptive first strike designed to eliminate North Korea’s nuclear and missile capabilities— or an attack that the North might interpret as such— would not qualify as an operation with a limited objective. As noted above, should it fail or be identified before taking place it carries a high risk of the North actually using its nuclear weapons once it has the capability to do so in the future.
Consequently, if such a risky operation is to be undertaken it must be done using the full spectrum of capabilities at one’s disposal (with the possible exception of nuclear weapons). South Korea has been adding increasingly effective missiles to its arsenals. Nonetheless, there is little doubt that the U.S. military has the greatest chance of undertaking a successful first strike against North Korean nuclear and missile targets and therefore it should be included in any such operation. This is all the more true given that the U.S.—which has 26,000 troops in South Korea— would hardly be unaffected by a failure on South Korea’s part to destroy the North’s nuclear and missile sites.