In North Korea, ‘Surgical Strike’ Could Spin Into ‘Worst Kind of Fighting’

The North has often threatened to turn Seoul into a “sea of fire,” but the vast majority of its artillery has a range of three to six miles and cannot reach the city, analysts say.

The North has deployed at least three systems, though, that can reach the Seoul metropolitan area: Koksan 170-millimeter guns and 240-millimeter multiple-rocket launchers capable of hitting the northern suburbs and parts of the city, and 300-millimeter multiple-rocket launchers, which may be able to hit targets beyond Seoul.

There are perhaps 1,000 such weapons near the Demilitarized Zone, many hidden in caves, tunnels and bunkers. But under a traditional artillery strategy, the North would not fire them all at once. Instead, it would hold some in reserve to avoid giving their positions away and to conserve munitions.

How much damage an initial attack would inflict depends on how many are used and on how much of the ordnance explodes. In 2010, North Korean forces fired about 170 shells at an island in the South, killing two civilians and two soldiers. Analysts later concluded that about 25 percent of the North’s shells failed to detonate.

A study published by the Nautilus Institute for Security and Sustainability in 2012 accounting for these and other factors such as population density concluded that the initial hours of an artillery barrage by the North focused on military targets would result in nearly 3,000 fatalities, while one targeting civilians would kill nearly 30,000 people.

The North could compound the damage by also firing ballistic missiles at Seoul. But Joseph S. Bermudez Jr., a North Korea expert at AllSource Analysis, a defense intelligence consultancy, said it was more likely to use missiles to target military installations, including American bases in Japan.

United States and South Korean forces could be put on alert and bracing for retaliation before any attempt to knock out North Korea’s nuclear program. But there is little they can do to defend Seoul against a barrage of artillery.

The South can intercept some ballistic missiles, with the recently installed Terminal High Altitude Area Defense system, as well as Patriot and Hawk systems. But it does not have anything like Israel’s Iron Dome that can destroy incoming artillery shells and rockets, which fly at lower altitudes.

Instead, South Korean and American troops would employ traditional “counterbattery” tactics — using radar and other techniques to determine the location of the North’s guns when they are moved out of their bunkers and fired, and then using rockets and airstrikes to knock them out.

David Maxwell, associate director for the Center for Security Studies at Georgetown University and a veteran of five tours in South Korea with the United States Army, said the Pentagon was constantly upgrading its counterbattery capabilities. But he added, “There is no silver bullet solution that can defeat North Korean fire before they inflict significant damage on Seoul and South Korea.”

Based on counterbattery efforts in the Iraq war, the Nautilus Institute study estimates that North Korea might lose about 1 percent of its artillery every hour to American and South Korean counterbattery fire, or more than a fifth of its arsenal after a day of fighting.

What makes the situation so dangerous is how easy it would be for either side to take action that leads the other to conclude an all-out war is imminent and escalate the battle. The United States and South Korea could hit targets besides artillery, including supply lines and communication facilities, for example. The North could send tanks and troops across the border and drop special forces into the South’s ports.

Especially perilous would be any hint that the United States and South Korea were preparing a “decapitation” strike against the North Korean leadership, which could lead a desperate Mr. Kim to turn to nuclear or biochemical weapons.

All things considered, analysts say, it could take American and South Korean forces three to four days to overwhelm North Korea’s artillery.

How much damage North Korea inflicts in that time depends in part on South Korea’s ability to get people to safety quickly. As more of the North’s guns are destroyed and people take cover, the casualty rate would fall with each hour.

The Nautilus Institute study projects 60,000 fatalities in the first full day of a surprise artillery attack on military targets around Seoul, the majority in the first three hours. Casualty estimates for an attack on the civilian population are much higher, with some studies projecting more than 300,000 dead in the opening days.

The Seoul metropolitan government says there are nearly 3,300 bomb shelters in the city, enough to accommodate all 10 million of its residents. In Gyeonggi Province, which surrounds the capital like a doughnut, the provincial government counts about 3,700 shelters. Many train stations in the region double as shelters, and most large buildings have underground parking garages where people fleeing artillery attacks can seek cover.

But critics say that the local authorities are unprepared for the chaos an artillery attack would cause and that the public is nonchalant about the prospect of war.

The South Korean government conducts emergency drills only five times a year, and they are fairly desultory affairs that last about 20 minutes, with people hunkering in buildings or stopping in their cars on the roads after sirens go off. Many residents have no idea where their nearest shelter is.