For more than a decade, conventional wisdom has held that North Korea could subject the South Korean capital of Seoul to devastating artillery attack.

With a greater metropolitan population of 24 million, Seoul has the largest population density of all the OECD countries, eight times more dense than New York City and three times more dense than Tokyo and Yokohama.

Aimed at Seoul, North Korea’s prodigious amount of artillery, particularly its 170mm Koksan guns and 240mm multiple rocket launchers, could kill “millions of people” in the event of war on the Korean Peninsula.

The “sea of fire” scenario first surfaced after the Clinton Administration decided not to attack North Korean nuclear facilities in 1994. Coincidence? Maybe, but since then it’s been used to trump discussion of any military action against North Korea, for whatever reason.

Uncertainty about how military action would play out, as well as the North’s unpredictability, means that virtually anything anyone proposed risked the “sea of Fire.” This haunting scenario has played a role in how policymakers and wonks view engagement with the North.

Is North Korea unpredictable? Yes. Does it have an enormous amount of artillery? Yes. Are many of the artillery pieces in cover? Yes? Could an artillery attack on Seoul kill “millions”? Probably not.

Critical questions

Roger Cavazos, associate analyst at the Nautilus Institute, has released a study on the actual feasibility of the “sea of fire.” As Cavazos points out, there are critical questions we should be asking about this apocalyptic scenario.

No one doubts that an artillery attack on Seoul is possible, but how quickly could South Korea’s civil defense system protect its people from an artillery attack? Would North Korea execute strictly a countervalue strike against the South or a mix of counterforce and countervalue? Would North Korea risk killing thousands of Chinese citizens living in South Korea? Can North Korea logistically support such an artillery attack? How quickly would the North’s artillery force be attrited by US / South Korean forces? How many artillery pieces are actually within range of Seoul?

The answers make it clear that the “sea of fire” is just not a realistic scenario. As Roger explains:

If the North Korean Peoples Army (KPA) were to start a doctrinal, conventional artillery barrage focused on South Korean forces, we could expect to see around 3,000 casualties in the first few minutes, but the casualty rate would quickly drop as the surprise wears off and counterbattery fires slow down the North Korean rates of fire.

If the KPA were to engage Seoul in a primarily countervalue fashion by firing into Seoul instead of primarily aiming at military targets, there would likely be around 30,000 casualties in a short amount of time. Statistically speaking, almost 800 of those casualties would be foreigners given Seoul’s international demographic. Chinese make up almost 70 percent of foreigners in Seoul and its northern environs, which means KPA might also kill 600 Chinese diplomats, multinational corporation leaders and ranking cadre children who are students in Seoul. Horrible, but nothing approaching “millions.”

Regarding the infamous Koksan guns and 240mm “Juche 100” multiple rocket launchers:

In a worst-case scenario, there are 700 artillery pieces capable of ranging most of Seoul. Not all the rockets or shells will explode. The most recent dud rate available from any DPRK artillery piece comes from DPRK attack on Yeonpyong Do and yields a dud rate of 25 percent. The source of such a large dud rate is unclear at this time, but again it is the only recent indicator available — to the North Koreans — as well as the rest of the world. If we see KPA suddenly testing all different types of artillery tubes and shell fuze combinations, it might indicate they lack confidence in their dud rates.

The power of those 700 artillery pieces is whittled down considerably in a wartime scenario. As the author points out, doctrinally 25 percent of the guns would be held back in reserve. The guns that are firing must be resupplied and the North’s logistics system is… not that great. American and South Korean forces will be hunting those guns and historically 1 percent of them will be taken out every hour. And one out of every four shells would likely be a dud.

Cavazos makes it clear that while a North Korean artillery attack on Seoul would be a tragedy, common assertions about such an attack do not stand up to scrutiny.

This story first appeared at Asia Security Watch, June 27, 2012.