By Troy Stangarone

Ever since the United States detonated a nuclear weapon over Japan at the end of World War II, nations have felt the need to pursue a nuclear weapons program. They have sought nuclear weapons as the ultimate means of deterrent, as a means to gain leverage over their adversaries, and as a form of international prestige. In the case of South Korea, the success of North Korea’s recent nuclear test and the heightened rhetoric for war coming out of Pyongyang has caused some leaders in Seoul to rethink the necessity of maintaining their own nuclear arsenal as a means of deterrence. However, this path, while potentially appealing, comes with significant political and economic costs that would ultimately make pursing an independent nuclear deterrent a mistake.

Why South Koreans Might Think They Need Nuclear Weapons

As the Cold War was dawning, the Soviet Union felt it needed nuclear weapons to maintain parity with the United States. France, which remained outside NATO’s military command for 43 years and has always sought the ability to project military power independent of the United States, followed the Soviet Union and the United Kingdom’s acquisition of nuclear weapons to bolster its own military might. Even South Korea previously sought nuclear weapons after the United States withdraw from Vietnam. The lure of nuclear weapons is so strong that Saddam Hussein allowed other countries to think he might have them as a means of deterrent.

Since South Korea gave up its own ambitions to acquire nuclear weapons in the 1970s, it has relied on the protection of the United States nuclear umbrella. However, with North Korea’s successful missile and nuclear tests, withdrawal from the Korean War armistice, and increasingly hostile rhetoric, some in South Korea have begun discussing the option of Seoul gaining its own nuclear deterrent or seeking the return of U.S. tactical nuclear weapons to the peninsula as the New York Times recently reported.

Under the United States’ nuclear umbrella, South Korea depends on the extended deterrence of the United States’ nuclear weapons to preclude either a nuclear attack or a large scale conventional attack. The principal of extended deterrence works as long as both potential adversary and the country under protection believe that the U.S. promise of nuclear retaliation is credible. The other challenge is that, while extended deterrence has worked to deter major attacks on U.S. allies, it has not proven successful in preventing the small scale attacks North Korea has engaged in with the sinking of the Cheonan and the shelling of Yeonpyeong-do.

However, it is not just North Korea’s actions that have prompted discussions of changes in South Korea’s nuclear posture. According to polling by the Asan Institute for Policy Studies, South Koreans have begun to lose faith in the credibility of the nuclear umbrella. In 2012, only 48 percent of South Koreans thought the United States would respond with nuclear forces if South Korea suffered a North Korean nuclear attack. That is a 7 point decline from the previous year. At the same time, public support for the development of South Korea’s own nuclear weapons program has grown from 56 percent in 2010 to 66 percent shortly after North Korea’s third nuclear test.

The Potential Costs of Going Nuclear

While a good deal of attention has been paid to the potential impact of the reintroduction of U.S. nuclear weapons to the Korean peninsula or the development of South Korea’s own nuclear weapons on Seoul’s own deterrent posture, relatively little attention has been paid to the potential political and economic costs South Korea might face if it choose to develop its own nuclear weapons.

South Korea developing its own nuclear deterrent would in many ways be unprecedented. No state with a Mutual Defense Treaty with the United States has acquired a nuclear weapon since the advent of the Nuclear Non-Proliferation Treaty (NPT). Additionally, other than North Korea, all of the states that have developed nuclear weapons since the NPT have done so while outside of the NPT. North Korea conducted its first nuclear test after it’s withdraw from the treaty.

Additionally, Seoul would be in violation of its NPT responsibilities, and if it withdrew from the treaty, join North Korea as the only countries to withdraw from the NPT. It would likely find itself unable to draw upon the Nuclear Suppliers Group, which provides much of the fuel needed to power nuclear plants.

It would also find itself in violation of its civilian nuclear agreement with the United States, which inhibits its ability to use nuclear plants with any U.S. content for weapons development, and see the current talks to extend the agreement grind to a halt.

South Korea’s Domestic Nuclear Program

The development of a nuclear deterrent would likely end South Korea’s goals of becoming a nuclear exporter. It could also potentially impact South Korea’s own domestic nuclear program. South Korea has a robust domestic nuclear program which meets 13 percent of its domestic energy needs and a desire to become a player in the international market for nuclear power exports.

In 2009, South Korea won a $40 billion contract to manage and construct four nuclear power plants in the United Arab Emirates. This was seen as a first step in South Korea’s efforts to become a significant player in the nuclear export industry and potentially build 80 plants worldwide by 2030. That contract would likely be at risk as well as South Korea’s own long term fuel supply.

Economic Sanctions

In recent years, both North Korea and Iran have seen economic and financial sanctions placed on their economies as they either pursued or were suspected of pursing nuclear weapons. South Korea would also likely face either bilateral or multilateral economic sanctions.

India and Pakistan faced sanctions for their pursuit of nuclear weapons. While UN sanctions only called on countries not to supply technology, equipment, or material that could benefit their programs, both faced additional U.S. sanctions which prohibited military assistance and support for loans in financial institutions.

Because of the unique nature in which South Korea would develop nuclear weapons, it is hard to truly know what the consequences might be. However, on a minimal level history would suggest that Seoul would find itself facing economic sanctions and limits on its own nuclear program unless it pursued nuclear weapons in the face of eminent war. Perhaps South Korea, due to its international reputation and sympathy for the challenges it faces from North Korea could minimize these costs, but there are no assurances that it would not face the same type of sanctions that Iran and North Korea face today.

While North Korea clearly presents unique challenges to South Korea, there is no reason to believe that the U.S. nuclear umbrella is unreliable. At the same time, the costs of pursing a nuclear weapons program in the absence of a clear failure of deterrence means that while there will likely continue to be robust debate about the option of developing nuclear weapons as long as North Korea continues its provocations, it is not an option which South Korea is likely to seriously pursue.

Troy Stangarone is the Senior Director for Congressional Affairs and Trade at the Korea Economic Institute of America. The views expressed here are his own.

Photo from U.S. Pacific Fleet’s photostream on flickr Creative Commons.