Going Nuclear Wouldn’t Be Easy for South Korea

The option has been revived in the wake of North Korea's latest provocations.

North Korea has conducted four nuclear tests, pushed boundaries with its missile tests, is pursuing second strike capabilities, and shows no indication of slowing down. South Korea in response has made a strategic bet that closing the Kaesong Industrial Complex can help to create leverage internationally to convince Pyongyang to abandon its nuclear ambitions, but some in Seoul and Washington are suggesting that South Korea should consider developing its own nuclear umbrella as leverage in talks with North Korea. However, this would be much more difficult than proponents generally acknowledge.

Since abandoning its own pursuit of nuclear weapons in the 1970s, South Korea has relied on United States nuclear umbrella for extended deterrence to prevent either a large scale invasion by the North or a nuclear attack. However, as North Korea continues to advance its nuclear and missile programs in spite of the international sanctions, it is understandable that experts and policy makers would look for new ways of deterring North Korea and incentivizing it to roll back its nuclear weapons and missile programs.  

Arguments in favor of South Korea developing an independent nuclear deterrent tend to center around four arguments. First, that once North Korea has a range of deployable nuclear weapons with a second strike capability the military balance on the peninsula will have changed in a dangerous way. Second, that the international community has been ineffective in convincing North Korea to give up its nuclear weapons program, jeopardizing South Korea’s national security. As a result South Korea needs to take responsibility for its own defense. Only with its own nuclear deterrent would Seoul have the ability to negotiate the elimination or reduction of Pyongyang’s program. Third, that whether now or in the future the protection of the United States might become untenable. This is often expressed in the question of whether the United States would risk Los Angeles to save Seoul or concerns over future U.S. defense cuts. And lastly, that the prospect of a nuclear armed South Korea, and potentially Japan, might focus minds in Beijing on resolving the problem of North Korea.

The South Korean public has also shown support for domestic nuclear weapon. Polls taken shortly after the closing of the Kaesong Industrial Complex show domestic support ranging from 52.2 percent to 67.7 percent and polling done by the Asan Institute for Public Policy after North Korea’s third nuclear test indicated that South Korean faith in U.S. extended deterrence was waning.

However, South Koreans are rarely asked if they would be willing to bear the costs of a domestic nuclear weapon. Those cost would likely come in the form of diminished international standing, economic hardship, and uncertain strategic benefits.

For South Korea to develop its own nuclear weapons program it would have to join North Korea as the only country to withdraw from the Nuclear Non-Proliferation Treaty (NPT), an ignominious club for sure. Withdrawal would dent Seoul’s growing international standing and make it the only member of MIKTA, an emerging club of middle powers, to have a nuclear weapon, something which would not enhance South Korea’s middle power prestige.

While a loss of international stature to ensure domestic security might be an acceptable trade off, there would likely be economic costs as well. Developing a nuclear weapon would have consequences for South Korea’s own nuclear industry. Nuclear power provides a third of South Korea’s electricity and represents 13 percent of its primary energy consumption. Lacking adequate domestic reserves of nuclear fuel, South Korea is dependent upon members of the Nuclear Suppliers Group which conditions supply on the non-proliferation of nuclear weapons. Pursuing a nuclear option would put the fuel supply for South Korea’s domestic reactors at risk.