By Emma Sandifer
The question of whether a nuclear deterrent might be necessary for South Korea has experienced a resurgence over the past few years, becoming a “mainstream feature of South Korea’s national security discourse”. With recent escalation in the pace of North Korea’s nuclear provocation, China’s aggressive buildup of its nuclear arsenal, and waning confidence in the U.S. commitment to extended deterrence, the public perception in South Korea has reflected a sense of increased vulnerability. Consequently, public polling in January of this year found that 71 percent of South Koreans support the return of nuclear weapons to their country — even if it means engaging in indigenous development. In 2023, South Korean President Yoon Suk-yeol spoke openly, for the first time, of the perceived need to either redeploy American non-strategic nuclear weapons on the Korean Peninsula or build their own. The reality is that it is not in South Korea’s national interest to have a nuclear weapon — politically, militarily or economically.
Despite this, the debate on the Peninsula is real and the country’s legitimate security concerns should be considered. With the North making regular threats, the trepidations of South Koreans are understandable and the need to take measures to reduce the threat from the North clear, but it remains questionable if nuclear weapons would serve such a purpose. More likely, a South Korean nuclear weapon would serve to fuel a destabilizing arms race in Asia and could actually undermine South Korea’s negotiating position vis-a-vis North Korea.
Politically, a nuclear weapon would not make South Korea safer. As an active member of multiple non-proliferation agreements including the Nuclear Non-Proliferation Treaty (NPT) and the 1992 Joint Declaration on the Denuclearization of the Korean Peninsula, South Korea uses these agreements to condemn North Korea’s proliferation and mobilize international support against the nuclear activities of its adversary. South Korea’s own proliferation would jeopardize its ability to do so as well as damage its standing in the international community and its relationship with its primary security ally, the United States.
Militarily, a nuclear weapon would not make South Korea safer. The ROK already has the conventional capabilities needed to strike any target in North Korea through the use of short-range ballistic missiles and precision strike weapons, has recently committed $81 billion toward strengthening its pre-existing defense capabilities, and has established a strategic command to oversee its “three-axis” defense system. Nuclear weapons would add little while increasing paranoia north of the DMZ.
To reinforce reliability of the U.S. commitment to extended deterrence, Presidents Joe Biden and Yoon announced the Washington Declaration in early 2023, as well as the creation of the bilateral Nuclear Consultative Group. In early November, the two countries updated their Tailored Deterrence Strategy agreement for the first time in a decade to reflect their “ironclad” commitment to collective security underscored by the symbolic deployment of major U.S. military assets to the country, such as a nuclear ballistic missile submarine and a nuclear capable B-52 bomber. South Korea is not only conventionally capable of deterring a nuclear attack by North Korea, but it is also protected by a renewed commitment to extended deterrence by the United States, making the development of a nuclear weapon redundant and escalatory.
Economically, a nuclear weapon would not make South Korea safer. A withdrawal from the NPT would bring an array of potential sanctions with the ability to cause real economic damage. Even if the impact of these sanctions is mitigated by allies to protect regional security interests, the impact of potential Chinese sanctions would be severe. Moreover, this withdrawal would impact international cooperation with Seoul’s nuclear energy program, an economic and energy priority.
Thus, although a nuclear weapon might make South Koreans feel safer, at least temporarily, it would not make the country any more secure. Conversely, creation of a nuclear weapon will undermine South Korean efforts to protect itself against a North Korean threat. Instead, the legitimate security concerns voiced by South Koreans could be addressed by strengthening conventional capabilities as well as engaging with international arms control efforts and dialogue across the DMZ. Such measures would do more to promote confidence among Korean citizens than engaging in a destabilizing arms race.