US help isn’t enough: South Korea wants its own nuclear weapons

On Sept. 2, South Korea’s Kim Yong-hyun, at his confirmation hearing for defense minister, said he would be “open” to his country developing nuclear weapons.

“That is included among all possible options,” Kim announced.

Kim’s comment is nothing less than a public vote of no confidence in the U.S., the South’s protector for over seven decades.   

The South Korean public certainly agrees with Kim. A Gallup Korea poll released in February shows that 72.8 percent of the population favored the possession of nukes. 

Such a position is understandable. North Korea, separated from the South by the narrow strip of the Demilitarized Zone, today has, according to the Stockholm International Peace Research Institute, up to 50 nuclear weapons. Some believe the North has enough fissile material for 60 more. 

The South, in contrast, is still a party to the Nuclear Nonproliferation Treaty, which prohibits it from developing and possessing nuclear weapons. 

North Korea, with its arsenal, threatens South Korea. On Aug. 4, Kim Jong Un, the North’s bellicose leader, announced the deployment of “250 new-type tactical ballistic missile launchers” to positions near the DMZ. The launchers can carry four tactical nuclear weapons each, so Kim was not exaggerating when he boasted they have “great military significance.” 

The U.S. led a United Nations coalition that defended South Korea in the Korean War. Washington and Seoul inked a mutual defense treaty in 1953, the year the armistice was signed. Today, about 24,200 active-duty American military personnel remain in the South to enforce the U.S.-South Korean mutual defense treaty.  

The alliance “forged in blood” has kept the peace. The pact is still needed because no peace treaty formally ended the Korean War, and in any event, the South did not sign the armistice.  

To keep the peace, the U.S. has pledged to use nuclear weapons to defend its South Korean ally. On July 11, President Joe Biden and President Yoon Suk Yeol issued a joint statement, the “U.S.-Republic of Korea Guidelines for Nuclear Deterrence and Nuclear Operations on the Korean Peninsula.”

The two leaders emphasized that “any nuclear attack by [North Korea] against [South Korea] will be met with a swift, overwhelming, and decisive response.” To drive home the point, Biden added that the “U.S. commitment to extended deterrence to [South Korea] is backed by the full range of U.S. capabilities, including nuclear.” 

The explicit guarantee apparently is not good enough for a majority of South Koreans. It is not entirely clear, however, that they understand the implications of their nuclear ambitions. Some even think that nuclear weapons would make South Korea less safe.  

How so? The South, by either withdrawing from the Nuclear Nonproliferation Treaty or openly violating its obligations, might effectively end its alliance with the U.S. Kim Yong-hyun is not worried about what he calls “activating a Plan B” and developing the bomb. He thinks the U.S. would remain an ally.

Is Kim right? The U.S. remains allies with Britain and France, nuclear weapon states. More to the point, Washington fully supports Israel, widely believed to have first built nukes in the late 1960s. 

David Maxwell, who served five tours of duty with the U.S. Army in Korea, raises a problem for Seoul. 

“Those who advocate for the development of indigenous nuclear weapons by South Korea are providing direct support to Kim Jong Un’s political warfare strategy to subvert the [South Korean] government and society and drive a wedge in the alliance,” he told me. 

“Kim welcomes the call for South Korean nuclear weapons because he likely does not fear them and will not be deterred by them. More importantly, South Korea’s possession of nuclear weapons demonstrates a lack of trust in the U.S. nuclear umbrella and extended deterrence.” 

So what should Seoul do?  

“A better alliance course of action is to continue to develop the Nuclear Consultative Group,” says Maxwell, who is also vice president of the Washington, D.C.-based Center for Asia Pacific Strategy.  

The Nuclear Consultative Group was established by the U.S. and South Korea to implement the April 2023 Washington Declaration, a joint statement between Biden and Yoon affirming the alliance between the two countries. In the Declaration, issued to mark the 70th anniversary of the mutual defense treaty, Yoon reaffirmed the South’s commitment to refrain from developing nuclear weapons.  

Maxwell suggests that the U.S., to enhance trust, could “examine the redeployment of U.S. theater nuclear weapons to Korea and the region.” President George H. W. Bush removed them from the Korean peninsula and elsewhere in 1991 in the hope that such a move would, among other things, entice North Korea to stop building its own arsenal. 

The enticement did not work. Kim Il Sung, the founder of the North Korean state and its leader at the time, was interested in possessing his own deterrent, even though he was then protected by the largest arsenal of the time, the store of Soviet nukes. Now, the other Korean state is also thinking of going its own way.  

South Korea, under pressure from Washington, abandoned its nuclear weapons program in the 1970s. Now, the U.S. will have to work hard to stop its Korean ally from resuming that effort. 

If South Korea loses confidence in America and builds its own deterrent, Japan, Taiwan and others could decide to build nuclear weapons too. South Korea, thanks to Kim Yong-hyun, is now a test for Washington — and the world’s nonproliferation regime. 

Gordon G. Chang is the author of “The Coming Collapse of China” and the upcoming “Plan Red: China’s Project to Destroy America.” Follow him on X @GordonGChang.