by Carl Parkin*
In its first few months, the second Trump administration has disrupted long standing alliance relationships by questioning existing arrangements. The project to recast the United States’ role in its alliances won’t end with Europe, and if nominations are anything to go by, South Korea may be next on the burden-sharing chopping block. Elbridge Colby, just confirmed for a senior position in the Department of Defense, has told South Korea to step up in the management of its own defense, and has even indicated that nuclear weapons development could be on the table in future alliance negotiations.
The suggestion to nuclearize the Southern end of the Korean Peninsula doesn’t come out of nowhere for Korea-watchers. Officials in South Korea’s People Power Party (PPP), alongside prominent academics, have expressed repeated support for nuclear acquisition, indicating a perceived lessening of U.S. commitment to its alliances as a primary motivation for the move. Prominent South Korean elites have been angling for ‘nuclear latency’ — the ability to rapidly acquire a usable nuclear weapon — since far before Trump’s inauguration. Additionally, polls demonstrate that nuclearization is widely supported among the South Korean populace. With 72.8% in favor, the issue could transcend the nation’s political divisions, indicating that even a resurgent Democratic Party (DP), despite its dovish attitude toward North Korea and anti-nuclear sentiments, would likely have to give it some consideration.
However, South Korea would face heavy strategic and economic costs if it chose to develop a nuclear weapon. These costs would not be bearable by the Republic alone, and would necessitate the United States taking on more of a burden in the country’s defense in the short term. Therefore the United States should continue to oppose a South Korean bomb, as it would neither further burden-sharing goals nor facilitate an effective China policy.
Embarking on the journey to nuclear development would make South Korea’s security conditions even more perilous and demanding. Firstly, mandatory sanctions from international organizations in response to the ROK breaking its NPT obligations would have harsh consequences for the Republic. The Nuclear Suppliers Group, an international organization of nuclear materials exporters, prohibits its members from providing materials to nations that have breached or terminated their agreements with the International Atomic Energy Agency (IAEA). As nuclear energy provides roughly one-third of South Korea’s electricity, falling out of favor with nuclear materials exporters would harm not just the nation’s budding nuclear weapons program, but its ability to meet its energy needs.
Additionally, China, South Korea’s foremost trading partner, has voiced and demonstrated an interest in maintaining a status quo on the Korean Peninsula, and would likely levy sanctions in an attempt to avoid the escalation that South Korean nuclear development could cause. Given South Korea’s relative economic dependence on China, these sanctions would prove a knife in the side of the Republic’s economy, further imperiling its security.
Despite the advanced nature of South Korean nuclear technology, developing and fielding a meaningfully deterrent nuclear arsenal is technologically and bureaucratically complex, and takes time. A window would follow its decision to nuclearize in which South Korea would be politically isolated on account of that decision, economically weakened by likely sanctions from China and the Nuclear Suppliers Group, and not yet in possession of a nuclear weapon. This would be a situation of extreme risk for the Republic and could invite DPRK adventurism.
Ostensibly, a South Korean bomb would be a boon for President Trump’s burden-shifting priorities, possibly allowing the United States to reduce its role in South Korea’s defense. However, during this window of vulnerability, it’s unlikely that South Korea would help their main security guarantor out the door. Domestic support in the Republic for nuclearization drops to 35-40% in scenarios where support from the United States is absent. South Korea simply wouldn’t develop the bomb without U.S. protection during its window of vulnerability. In addition, the considerable resources needed for a nuclear weapons capability would not be available for other defense purposes, leaving the ROK paradoxically less able to defend itself in exchange for a capability it would hope never to use.
The United States should not entertain South Korea’s nuclear ambitions whatsoever. Sponsoring South Korea’s path toward the bomb would further escalate the United States’ already tense relationship with China. In 2016, U.S. deployment of missile defenses on South Korean shores provoked significant PRC protest. One can only imagine the scale of pushback that the United States could expect from nuclearization, a far more escalatory action, in today’s far tenser security environment. Comparisons to the Cuban Missile Crisis come easily. The United States should exercise its strategic empathy, recognizing the insecurity a South Korean bomb would instill in China and prioritizing de-escalation of great power tensions over a misguided attempt at burden shifting.
*Editor’s note: Writing for the Center’s new Next Up in Arms Control series, Carl Parkin is a Junior at Franklin & Marshall College majoring in Government and Geosciences, and a Foreign Policy Futures Fellow with the Stimson Center. His interests include restraint in U.S. Foreign Policy, and, of course, all things nuclear.
DISCLAIMER: Next Up in Arms Control is a way for the Center to present an opportunity for dialogue and provocation through the thoughtful exchange of ideas and opinions on new or different ways to reduce and eventually eliminate nuclear threats. Opinions are the authors’ alone and not necessarily reflective of Center’s positions on the issues addressed.
