The Case for South Korea to Go Nuclear

North Korea’s nuclear and missile threats against South Korea and the United States have continued to escalate significantly. Against the backdrop of these serious nuclear threats, both Seoul and Washington should be prepared for the worst-case scenario, which is a nuclear war with North Korea.

In April, North Korea announced its intention to forward-deploy tactical nuclear weapons, and in September Pyongyang adopted a new nuclear policy law, which allows the country to carry out a preemptive nuclear strike against South Korea. From the end of September to early October, North Korea’s “tactical nuclear operation units” conducted launching drills of missiles designed to strike potential South Korean targets such as airfields, ports, and command facilities. Additionally, on October 4, North Korea fired an intermediate-range ballistic missile at a normal angle – not a high angle – so that the missile overflew Japan into the Pacific Ocean. The test once again demonstrated North Korea’s capability to reach the U.S. territory of Guam in case of U.S. intervention in inter-Korean military clashes.

With North Korea’s nuclear capability to reach U.S. territory, most South Korean and American experts have questioned if the United States would actually provide nuclear retaliation against the North should South Korea be attacked by North Korea’s tactical nuclear weapons. It would be difficult for the United States to retaliate with nuclear weapons against North Korea when Pyongyang will also launch nuclear attacks on the U.S. homeland – probably Washington, D.C. or New York City – in retaliation. No American president would be able to make such a decision, which will claim hundreds of thousands, if not millions, of Americans’ lives. Even if the future brings a scenario of nuclear sharing or redeployment of U.S. tactical nuclear weapons to South Korea, it will be the U.S. president who has the authority to press the nuclear button. That means deployment of U.S. nuclear weapons to South Korea will not entail major difference from the current extended deterrence system.

This is also what Pyongyang thinks: North Korea does not expect the U.S. to unfold its nuclear umbrella, taking a risk of a nuclear war with North Korea. It is why the North made a bold action by launching a short-range ballistic missile as a response to the redeployment of a U.S. nuclear-powered aircraft carrier to the Korean Peninsula’s east coast.

It is anticipated that in the future, North Korea will launch an intercontinental ballistic missile (ICBM) at a normal angle into the Pacific Ocean to show off its capability to re-enter the atmosphere and to reach the U.S. homeland. It is also expected that North Korea will build nuclear-powered submarines, as presented during the Eighth Congress of the Workers’ Party of Korea in 2021, to display its second-strike capability.

As North Korea’s nuclear arsenal has grown rapidly, the threat it poses to South Korea and the U.S. also grows significantly. However, successive administrations of both countries have been chasing the mirage of “North Korean denuclearization,” without coming up with realistic solutions to the North Korean nuclear issue. Recently, Jeffery Lewis, an expert on nuclear nonproliferation at the Middlebury Institute of International Studies, claimed in an article for the New York Times that it’s time for the United States to admit the fact that its efforts to denuclearize North Korea have failed, and to accept that North Korea has nuclear weapons. If North Korean nuclear weapons were threats only to the United States, it would be reasonable for the U.S. administration to recognize North Korea as a de facto nuclear state. However, in a situation where North Korean nuclear weapons are a more direct threat to South Korea, a U.S. acknowledgement of North Korean nuclear weapons will cause a sense of betrayal among South Koreans.

In order to de-escalate tensions and to prevent nuclear war with North Korea, American policy decision-makers and academics need to consider the nuclear armament of South Korea as an option. A nuclear-armed South Korea will be able to start negotiations for nuclear arms reduction with the North. According to various polls conducted in 2021 and 2022, more than 70 percent of South Koreans – 74.9 percent, according to the SAND research institute’s figures released last June – support the country’s indigenous nuclearization out of the fear of North Korean nuclear bombs. That figure may exceed 80 percent if North Korea carries out a seventh nuclear test.

While some Korean right-wing politicians demand redeployment of U.S. tactical nuclear weapons to address the North Korean nuclear threat, the South Korean public prefers developing their country’s own nuclear weapons. Last December, the Chicago Council on Global Affairs conducted a survey of 1,500 South Koreans and 67 percent of them replied that they prefer “indigenous nuclear weapons development” to “deployment of American nuclear weapons.” Only 9 percent of the respondents prefer the latter.

Some American experts are concerned that South Korea’s nuclear weapons development would lead to a weakened South Korea-U.S. alliance and bring South Korea closer to China. However, that scenario is not likely to be realized. According to the “Unification consciousness survey 2022” published on September 22 by the Institute for Peace and Unification Studies (IPUS) at Seoul National University, when asked the question “Which country do you feel the closest to?” 80.6 percent of the respondents chose the U.S., while 9.7 percent replied North Korea, followed by Japan (5.1 percent), China (3.9 percent), and Russia (0.5 percent). The absolute majority, four-fifths of the respondents, feel close ties to the United States while South Koreans’ affinity for China is very low. It is hard to expect that South Korea’s nuclear armament will reverse these sentiments, either toward the United States or China.

Rather, South Koreans’ confidence in the alliance will collapse if the U.S. exhibits a reluctance to retaliate with nuclear weapons against North Korean nuclear attacks on the South. On the contrary, if South Korea pursues nuclearization, the country can respond to the North’s nuclear attacks with its own nuclear arsenal. This will free the United States from the conundrum of whether to use nuclear weapons to defend its East Asian ally. In the end, the U.S. homeland and its citizens’ lives will be also free from the threat of North Korea’s nuclear bombs. Additionally, a nuclear-armed South Korea will make North Korea approach using its nuclear weapons with more prudence, raising the threshold for using nuclear weapons.

To sum up, Seoul’s nuclearization will benefit both South Korea and the United States by lowering the possibility of North Korea’s use of nuclear weapons on the Korean Peninsula and sparing the U.S. from a nuclear war with North Korea. Nevertheless, the South Korean administration has failed to seriously consider the option of nuclearization, fearing the possible strong opposition and severe sanctions imposed by Washington. It is thus recommended that the U.S. administration suggest closed-door talks through bilateral high-level meetings to discuss this issue for mutual benefit.

The “South Korean nuclearization card” will deter North Korea’s nuclear threats; it will also encourage China to engage itself more actively in resolving North Korea-related issues. Therefore, it is very irrational for South Korea-U.S. alliance not to play with this card. If South Korea declares that “we have no choice but to withdraw from the NPT in case of North Korea’s seventh nuclear test,” the North will be more strained since the South has the raw materials to produce more than 4,000 nuclear warheads. In this case, China will also pressure North Korea not to carry out the seventh nuclear test because China does not want a worst-case scenario in which Seoul’s nuclearization leads Tokyo and Taipei to also develop nuclear weapons.

If North Korea still conducts a nuclear test, the South Korean government needs to declare, along with its withdrawal from the NPT, that “we will execute our plans for nuclear armament unless North Korea returns to the table of negotiation to discuss the denuclearization with South Korea, the U.S., and China within a six-month period.” Such a declaration of “conditional nuclear armament” by South Korea will stop Pyongyang from ignoring non-nuclear South Korea, and the North will start considering seriously returning to the negotiation table. Beijing will also urge Pyongyang to return to the denuclearization talks, applying maximum leverage, to prevent a nuclear domino effect that Seoul’s nuclearization may trigger in Japan and Taiwan.

Washington and Seoul can discuss the actual nuclearization of South Korea should these two steps to put pressure on North Korea and China fail. However, now is the time for the South Korea-U.S. alliance to play with the card of “Seoul’s nuclearization” to disturb Kim Jong Un. Otherwise, we will all regret it.