What North Korea lacks in sophistication it makes up for in guile. Its answer to any attack would go beyond conventional means to include its experienced commando force, cyberwarfare capability and submarine force, at the very least. Though North Korea has chemical weapons, they are probably no more effective than its air force and surface navy. Still, there's a psychological shock value attached to their use.
Pyongyang will do everything it can to impose a cost on any belligerent force. If the United States wishes to denuclearize North Korea, it will have to accept the consequences, as will South Korea and possibly even Japan. The United States would greatly prefer a diplomatic solution, but this has not worked well in the past. Even tougher sanctions imposed in March did little but harden Pyongyang's resolve. And in avoiding a messy, if short-lived conflict, the United States and South Korea may have set themselves up for future angst when Pyongyang unveils a strategic nuclear deterrent.
In addition to missiles equipped with high explosives, or possibly even nuclear devices, Pyongyang is known to have a significant stockpile of chemical warfare agents. There are also legitimate concerns about biological weapons development, but recent estimates indicate North Korea may have only samples of biological agents at the ready. This is a far cry from producing agents on a scale significant enough to be used offensively — huge batches have to be grown, maintained and eventually replaced, which is a monthslong cycle. Perhaps Pyongyang will have more biological weapons down the line, but that will not help it retaliate against the United States in the short term.
According to most sources, North Korea's stockpile of chemical agents is limited to precursors of chemical weapons and less complex agents. North Korea has the capacity to produce vast amounts of Sarin and VX gas, but for our purposes only readily available weaponized stockpiles are relevant. Since 2008, the assessed total metric tonnage of chemical agents North Korea possesses has stagnated at around 2,500 to 5,000. Of this stockpile, however, only a marginal amount would be useful in a counterstrike scenario: Estimates indicate only 150 missile-ready warheads exist for these chemical weapons. Though different missiles have varying payload capacities, less than 1 percent of the North Korean chemical weapons stockpile could be launched during an immediate response.
This stockpile is also rapidly aging. Stored agents lose efficiency, and unknown quantities of Pyongyang's chemical weapons stockpile may have become entirely ineffective. That said, the value of North Korean chemical weapons lies in their psychological impact. Sporadic attacks with chemical weapons are enough to cause widespread panic, especially among civilians. Furthermore, protection against chemical agents is cumbersome and costly. Though Pyongyang will not be able to use chemical weapons to its full advantage, even modest use can have an outsized impact.
Commando and Sabotage Threat
One of the most credible weapons available to the North Koreans in a war with South Korea and the United States is Pyongyang's large commando and sabotage force. The North Koreans, for decades aware of their growing conventional imbalance with the South, have invested heavily in the asymmetric capability that a commando force brings to the table.
Capable of being inserted into South Korea through tunnels, submersibles and aircraft such as the low-signature Antonov An-2, specialized North Korean commando units could wreak havoc in the South by attacking key infrastructure, logistics nodes, and command-and-control facilities. These attacks, when combined with other conventional and asymmetric strikes, can paralyze economic activity and would almost certainly lead to the diversion of a disproportionate amount of resources and personnel to track down and eliminate the units.
An increase in friendly fire events is another risk for South Korean forces, mainly on account of proven Northern tactics. North Korean special operations forces could deliberately wear South Korean uniforms, for instance, both enhancing their stealth and inciting confusion and suspicion.
The North Korean Air Threat
With more than 800 operational combat planes, the North Korean air force poses a considerable threat on paper. The reality, however, is that the force is for the most part obsolete. It suffers from a shortage of spare parts, and it has pilots who are far less trained than their South Korean and U.S. counterparts. Effectively, the North Korean air force is completely outmatched.
The North can still send massive waves of aircraft to attack the South, including Seoul. Even if some of these aircraft make it to their target, however, they are unlikely to survive the trip home through the dense and sophisticated air defense environment over South Korea.
Pyongyang has also increasingly sought to develop a drone capability, including unmanned aerial vehicles (UAV) with nascent attack capabilities. Because of their small size, they have a low profile and reduced radar signature, which means North Korea could use some UAVs in attack missions against the South. But sophisticated U.S. and South Korean air defense and jamming capabilities limit the overall threat.
The Naval Threat
Like the North Korean air force, the North Korean navy poses a real threat — within limits. Pyongyang relies on significant numbers of small, aging vessels, but they still carry a dangerous punch. Operating out of numerous staging areas, such as ports, coves and bays, North Korean surface vessels, including torpedo boats and missile craft, can surge out in hit-and-run attacks against U.S. and South Korean naval targets. Nevertheless, the North Korean surface fleet would not last long in battle and would primarily pose a threat in the initial stages of any conflict, before being steadily reduced through air and naval attack.
Outside the physical realm, North Korea has a cyberwarfare capability that could be used to strike back at South Korea or the United States. The majority of North Korean attacks have been fairly crude in nature, consisting of distributed denial-of-service (DDoS) attacks that prevent access to particular websites or online services for a brief time. Yet North Korean hacks have managed to exploit particular Trojans and malware that enable them to gain access to foreign systems not only for espionage purposes but also to remove data from disks. During one incident in 2013, financial and communications services were shut down as a result of North Korean cyber operations.
Many of these activities, including DDoS attacks and system penetrations, have been focused on spreading malware (malicious software) triggered to activate on historically significant dates. Though the effects of these cyberattacks have been notable in the past, this tactic likely requires too much lead time (for preparation and proliferation of the malware) to be used as an immediate response. It is unclear how quickly North Korean cyberwar elements would be able to mount a significant attack, though North Korean cyber units continue to use the DarkSeoul malware that was behind the 2013 attack. A cyber response would probably lag behind any other immediate physical retaliations, but because of the low risk it poses compared with physical methods of retaliation, cyber counterattacks following a strike against North Korea's nuclear program are highly likely. These attacks could temporarily take down critical infrastructure such as communications, financial or electricity networks, exacerbating any physical strike.
One thing is clear from examining Pyongyang's approach to retaliation: Any pre-emptive strike against North Korea's nuclear program will come at a hefty price. Though North Korea may not unleash the full power of its conventional and asymmetric capabilities for the purpose of revenge, it is an option that U.S. policymakers will have to deeply consider. Even lesser degrees of retaliation could pose a great threat to South Korea and to U.S. troops stationed there and nearby in places such as Japan.
The risk is not entirely one sided, though: The greater the retaliation from the North — particularly when it comes to the use of its most devastating tool, its conventional artillery forces — the more Pyongyang opens itself up to danger. North Korea is unlikely to expose itself to a point where it endangers its own ability to maintain sovereign integrity. Yet even below this threshold there is great potential for damage to South Korean political and business infrastructure in and around Seoul and, more important, a tremendous loss of human life. Throughout South Korea, critical elements of Seoul's industrial and military infrastructure would be targeted by ballistic missiles, sabotage or cyberattacks. And submarines can affect commerce by attacking ships around the peninsula. On top of the human cost, the economic toll could be devastating for South Korea.
There is an argument that the price paid must be weighed in the context of future potential costs, should attempts be made to denuclearize North Korea after it has developed a nuclear deterrent or, frighteningly, in the case of a North Korean first strike. Following this logic, there is a compelling case to be made that the cost of military intervention right now is justified, purely considering the alternatives. Almost any price would be acceptable if it meant avoiding a nuclear conflict in the future. But the nature of policymaking is such that leaders are judged by present costs and not by those that could occur down the line. It is an election year for the United States, and an outgoing president would not want to be remembered for a North Korean operation that went wrong.
Pyongyang understands that it has a narrow window to develop a credible nuclear deterrent, and once it does, the chance of hostile intervention becomes increasingly remote. Logic dictates that now would be the best time to strike, before North Korea can put the pieces of its program together, but Pyongyang is unlikely to give Washington an excuse to do so. Securing a diplomatic resolution is infinitely preferable to direct intervention, because even without the nuclear threat, attacking North Korea guarantees massive destruction in return. There will never be a perfect time to launch an operation to destroy North Korea's nuclear capability, but one thing is evident: Every year that goes by brings Pyongyang closer to a credible nuclear deterrent.
Part 4: How North Korea Would Retaliate
Part 5: The Cost of Intervention