US unlikely to send tactical nuclear weapons back to Korean Peninsula

U.S. Undersecretary of Defense for Policy Elbridge Colby arrives at a hotel in Seoul for talks with Foreign Minister Cho Hyun, Jan. 26. Newsis

The Pentagon’s push to give tactical nuclear weapons a greater role in defending U.S. allies in regional conflicts with China or Russia is raising questions in Seoul over whether U.S. nuclear weapons could return to South Korea more than three decades after their withdrawal.

According to media reports, the Pentagon is drafting a new nuclear strategy that would place greater emphasis on shorter-range tactical nuclear weapons in such conflicts.

South Korean experts, however, say the shift would not necessarily lead to the redeployment of U.S. tactical nuclear weapons here. They say a more likely consequence would be closer coordination between U.S. nuclear forces and South Korea’s conventional military capabilities, while warning that making nuclear weapons more usable could also increase the risk of escalation on the Korean Peninsula.

The United States withdrew all of its tactical nuclear weapons from South Korea in 1991, when former President George H.W. Bush ordered a global pullback of U.S. ground- and sea-based tactical nuclear arms. Then-South Korean President Roh Tae-woo responded by declaring the peninsula nuclear-free, leading to a landmark denuclearization agreement between Seoul and Pyongyang.

Calls for the weapons' return, or for a NATO-style nuclear-sharing arrangement, have resurfaced periodically as North Korea's nuclear arsenal has grown.

Rep. Yu Yong-weon of the main opposition People Power Party said a redeployment remains unlikely because nuclear weapons stationed in South Korea would be vulnerable to North Korean attacks.

“If tactical nuclear weapons were deployed to South Korea, they would realistically have to be stored at air bases,” Yu said. “North Korea would know where they are, making those bases priority targets in a contingency. The U.S. is well aware of this vulnerability, so I don’t think actual deployment in South Korea is very likely.”

A source familiar with the military, however, said forward deployment could also strengthen deterrence by making the possibility of U.S. nuclear use more credible, although South Korea’s small size could make such weapons particularly vulnerable.

Hong Min, a senior researcher at the Korea Institute for National Unification, also said Washington’s move should not be directly linked to the return of nuclear weapons to South Korea.

If the U.S. makes tactical nuclear weapons a more credible part of extended deterrence, Hong said, it could even weaken the argument that such weapons need to be physically stationed in South Korea.

Instead, he said the change could have greater implications for conventional-nuclear integration, which seeks to link U.S. nuclear capabilities with South Korea’s conventional forces in a contingency.

A U.S. military F-35 fighter jet flies over the National Mall during the “Salute to America” Independence Day celebration in Washington, D.C., July 4. The F-35A is certified to carry the B61-12 nuclear gravity bomb. AFP-Yonhap

“Strategic nuclear weapons are operated largely from the U.S. mainland, so there have been limits to how closely they could be integrated operationally with South Korea’s conventional forces,” Hong said.

“Tactical nuclear weapons could be operated from areas closer to the Korean Peninsula, including Japan or Guam, making the question of how they would work together with South Korean conventional forces much more concrete.”

Such a shift, however, could carry new risks.

A source familiar with the military described the greater reliance on tactical nuclear weapons as a “double-edged sword.”

“It would clearly strengthen deterrence, but it would also lower the threshold for nuclear war,” the source said, warning that the risk of a limited nuclear conflict triggered by miscalculation could also increase.

Hong said North Korea could view more usable U.S. tactical nuclear options not simply as another show of U.S. strategic assets but as a direct threat to the survival of its regime. That could prompt Pyongyang to further strengthen its nuclear and missile posture and reinforce the belief that it may need to use nuclear weapons before coming under attack.

The result, he said, could be a deeper security dilemma in Northeast Asia, with U.S. efforts to strengthen deterrence prompting North Korea and China to respond in kind and increasing the risk of miscalculation during a crisis.

The reported strategy is being developed under the supervision of Undersecretary of Defense for Policy Elbridge Colby.

“Our view is that we need credible nuclear options,” a senior U.S. Defense department official told NBC News, saying the aim is to give the president “realistic and credible options.”

The source familiar with the military said the shift could also reflect growing U.S. concerns that conventional forces alone may not be enough to deter multiple threats in East Asia, particularly as China expands its military capabilities, while military ties between North Korea and Russia deepen.

Historically, tactical nuclear weapons have taken on a greater role when conventional forces were considered insufficient to deter an adversary, the source said.

He also cautioned against viewing the reported strategy solely through the Korean Peninsula, saying its primary focus appears to be the broader East Asian security environment, particularly China and a potential Taiwan contingency.