North Korea, though a relatively poor, impoverished state, has amassed an impressive arsenal of weapons of mass destruction (WMD). Pyongyang has both nuclear and chemical weapons, and thanks to its industrious missile program can deliver them against both South Korea and Japan. A nuclear attack would likely trigger in-kind retaliation by the United States, with the resulting exchange creating unimaginable devastation across East Asia.
By far the most dangerous WMD in a second Korean War would be nuclear weapons. North Korea has conducted five nuclear tests, and experts estimate the country has a stockpile of fewer than ten bombs. Its opponent, the United States of America, has 1,411 nuclear weapons deployed and ready for use. South Korea believes that the North has the technology to put a nuclear warhead on a Rodong (also known as Nodong) missile. The North has 150 to two hundred Rodong missiles, each with an estimated range of up to 621 miles.
Thanks to an overwhelming edge in conventional weapons, it is unlikely the United States would be the first to use nuclear weapons. Although we don’t know if North Korea plans to use nukes in a war, we do know it is practicing to use them early in a conflict. Seoul is one obvious target, with the goal of decapitating the South Korean civilian government. North Korea’s latest nuclear-weapons test was in the twenty-kiloton range, and such a device detonated over the Han River would kill an estimated fifty-nine thousand people and injure another 136,000 more. With a little warning, Seoul’s extensive network of bomb shelters would reduce those numbers by a considerable degree.
Another target might be the port city of Busan, which would take in seaborne reinforcements from the United States. Sasebo Naval Base in Japan, headquarters of the U.S. Seventh Fleet’s amphibious forces, is also within Rodong range. A nuclear strike on the base would kill thousands of Americans and cripple the ability of the U.S. Navy, in the short term, to conduct an Inchon-style sea assault on North Korea’s coastline. An attack will also kill twenty-one thousand Japanese citizens and injure nearly thirty-eight thousand others.
North Korea might also use chemical weapons to negate key U.S. and South Korean advantages. It is thought to have chemical weapons from the principal five categories: riot, choking, blood, blister and nerve agents. In 2012, South Korea’s Ministry of National Defense estimated the North had a stockpile of between 2,500 and five thousand metric tons of chemical weapons. It further estimates the country has the ability to generate another 4,500 tons annually in peacetime, and twelve thousand tons in wartime.
The effectiveness of chemical munitions varies widely, depending on factors such as environmental conditions and method of dispersal, and it is difficult to predict how many casualties they might cause. They are, as a result, more of a harassing weapon than a destructive one. Chemical weapons could be used against U.S. and South Korean army and air force bases, naval ports, and air-defense facilities—no doubt including the new THAAD missile deployment. While an initial attack might kill or incapacitate relatively few, it would also deny facilities to UN forces until decontaminated. Against air bases such as Osan, a chemical attack would negate America’s local airpower advantage. Another possible target are the many South Korean reservist call-up locations scattered across the country, which would frustrate Seoul’s attempt to conduct a full-scale military mobilization.
A chemical attack against civilians is another possible scenario. North Korea has no compunction about putting civilians in the line of fire, as the 2010 bombardment of Yeonpyeong island demonstrated. The use of chemical weapons against civilians would not only cause thousands of casualties, but it could also cause panic and disorder that would hinder the UN war effort and increase pressure on the South Korean government to end the war.
The threat of a North Korean WMD attack is just one part of the equation; the other is the U.S. response. While the United States probably won’t retaliate to a chemical attack with chemical weapons, nuclear weapons are another matter entirely. Using nukes might not be necessary, but the United States may choose to use them anyway to reinforce the concept of nuclear deterrence. The use of nukes also increases the likelihood that North Korean leader Kim Jong-un, likely the only person in North Korea authorized to use nukes, would be killed.
The weapon most likely used against Pyongyang is a B61-12 gravity bomb delivered by B-2 bomber. A B61-12 nuclear bomb has a “dial-a-yield” capability of three hundred tons, 1.5 kilotons, fifteen kilotons, or fifty kilotons. A fifty-kiloton device detonated over the North Korean capital would kill an estimated 264,000 people and injure 783,000 more. These numbers constitute 4 percent of the overall North Korean population. A hundred-kiloton warhead delivered by a submarine-launched ballistic missile will kill and injure more than 1.3 million. Another option is to attack North Korean leadership facilities in and around the city with lower-yield devices, to keep civilian casualties down.
The United States could also conduct smaller, lower-yield nuclear strikes against North Korea’s known ballistic-missile bases in order to make sure any surviving nuclear forces could not execute second-strike contingency plans, such as an order to launch all remaining nuclear weapons once it was confirmed that Pyongyang had been struck. North Korea’s mobile missiles must rely on a road network amounting to just five hundred miles of paved roads, most of which are concentrated around cities. That would bring follow-up nuclear strikes closer to populated areas.
A war between North Korea and the United States will almost certainly open a Pandora’s box of destruction. While the use of nuclear weapons against South Korea could very well cripple the country, retaliatory strikes could kill and injure upwards of a million people in North Korea, destroying the government and provoking societal collapse. One thing is for sure: if such a war does start, North Korean leader Kim Jong-un will be among those killed. Not coincidentally, he is the person best positioned to prevent such a war from happening.
Kyle Mizokami is a defense and national-security writer based in San Francisco who has appeared in the Diplomat, Foreign Policy, War is Boringand the Daily Beast. In 2009, he cofounded the defense and security blog Japan Security Watch. You can follow him on Twitter: @KyleMizokami.
Image: B-1 Lancer awaits a pre-flight inspection at Ellsworth Air Force Base. Wikimedia Commons/U.S. Air Force