North Korea knows that war 'would be suicidal'

Visitors watch North Korean territory through binoculars at the unification observation post near the border village of Panmunjom, that has separated the two Koreas since the Korean War.

TOKYO // As tensions rise on the Korean Peninsula, one thing remains certain: all sides have good reason to avoid an all-out war. The last one, six decades ago, killed an estimated 4 million people.

North Korea's leaders know that war would be suicidal. In the long run, they cannot expect to defeat the United States and successfully overrun South Korea. War would be horrific for the other side as well. South Korea could suffer staggering casualties. The US would face a destabilised major ally, possible but unlikely nuclear or chemical weapons attacks on its forward-positioned bases, and dramatically increased tensions with North Korea's neighbour and Korean War ally, China.

Here's a look at the precarious balance of power that has kept the Korean Peninsula so close to conflict since the three-year war ended in 1953, and some of the strategic calculus behind why, despite the shrill rhetoric and seemingly reckless sabre-rattling, leaders on both sides of the Demilitarised Zone have carefully avoided going back over the brink.

'The Sea of Fire'

Even without nuclear weapons, North Korea has an ace in the hole. Most experts believe its claims to have enough conventional firepower from its artillery units to devastate the greater Seoul area, South Korea's bustling capital of 24 million. Such an attack would cause severe casualties – often estimated in the hundreds of thousands – in a very short period of time.

Many of these artillery batteries are already in place, dug in and very effectively camouflaged, which means that US and South Korean forces cannot count on being able to take them out before they strike. Experts believe about 60 per cent of North Korea's military assets are positioned relatively close to the Demilitarised Zone separating the countries.

North Korea's most threatening weapons are its 170mm Koksan artillery guns, which are 14 metres long and can shoot conventional mortar ammunition 40km. That's not quite enough to reach Seoul, which is 50km from the DMZ. But if they use rocket-assisted projectiles, the range increases to about 60km. Chemical weapons fired from these guns could cause even greater mayhem.

The North Korea experts Victor Cha and David Kang posted on the website of Foreign Policy magazine late last month that the North can fire 500,000 rounds of artillery on Seoul in the first hour of a conflict.

Even so, not everyone believes North Korea could make good on its "Sea of Fire" threats. The security expert Roger Cavazos, a former US army officer, wrote in a report for the Nautilus Institute last year that, among other things, North Korea's big guns have a high rate of firing duds, pose more of a threat to Seoul's less populated outer suburbs and would be vulnerable to counterattack as soon as they start firing and reveal their location.

"North Korea occasionally threatens to "turn Seoul into a Sea of Fire", he wrote. "But can North Korea really do this? ... The short answer is they can't; but they can kill many tens of thousands of people, start a larger war and cause a tremendous amount of damage before ultimately losing their regime."

First strikes and pre-emptive strikes

This is what both sides say concerns them the most.

North Korea says it is developing nuclear weapons and long-range missiles as a deterrent to keep the United States or South Korea from attacking it first. The reasoning is that Washington will not launch a pre-emptive strike if North Korea has a good chance of getting off an immediate – and devastating – response of its own.

Along with its artillery aimed at Seoul and other targets in South Korea, North Korea is developing the capacity to deploy missiles that are mobile, thus easier to move or hide. North Korea already has Rodong missiles that have – on paper at least – a range of about 1,300km, enough to reach several US military bases in Japan. Along with 28,000 troops in South Korea, the US has 50,000 troops based in Japan.

North Korea is not believed to be capable of making a nuclear weapon small enough to fit on a long-range missile capable of hitting the United States. But the physicist David Albright, the president of the Institute for Science and International Security, believes it may be capable of mounting nuclear warheads on Rodongs. In any case, Pyongyang is continuing to pursue advancements, apparently out of the belief that it needs nuclear-tipped missiles capable of reaching the US to have a credible deterrent.

The United States rejects the North's claim that such a deterrent is necessary, saying it does not intend to launch pre-emptive strikes against North Korea. At the same time, Washington has made it clear that it could.

During continuing Foal Eagle military manoeuvres in South Korea, two US B-2 strategic stealth bombers, flying from their base in Missouri, conducted a mock bombing run on a South Korean range. The B-2 is capable of carrying nuclear weapons, precision bombs that could take out specific targets such as North Korean government buildings, and massive conventional bombs designed to penetrate deep into the ground to destroy North Korean tunnels and dug-in military positions.

One big problem, however, is determining where the targets are.

During heightened tensions over North Korea's nuclear weapons programme in 1994, the US president, Bill Clinton, reportedly considered a pre-emptive strike, but decided the risks were too high.

China's dilemma

Without China, North Korea would not exist. The Chinese fought alongside the North Koreans in the Korean War and have propped up Pyongyang with economic aid ever since.

Beijing has grown frustrated with Pyongyang, especially over its nuclear programme. China and the US worked together in drafting a UN resolution punishing the North for its February 12 nuclear test.

But China still has valid reasons not to want the regime to suddenly collapse.

War in Korea would likely spark a massive exodus of North Korean civilians along its porous 1,300km border, which in turn could lead to a humanitarian crisis or unrest that the Chinese government would have to deal with. The fall of North Korea could pave the way for the United States to establish military bases closer to Chinese territory, or the creation of a unified Korea over which Beijing might have less influence.

China also has significant trade with South Korea and the United States. Turmoil on the Korean Peninsula would harm the economies of all three countries.

Patrick Cronin, an Asia expert at the Centre for a New American Security and a senior state department official during the George W Bush administration, said Beijing is helping set up back-channel negotiations with North Korea to ease the tensions. But he warned that the US is not likely to win China over as a reliable partner against North Korea beyond the current flare-up.

"There are limits to how far China and the US have coincidental interests with regard to North Korea," he said.