by SeungHwan Kim*
On October 24, 2025, President Donald Trump, aboard Air Force One en route to Asia, made a short remark with profound implications about North Korea (DPRK): “Well, I think they are sort of a nuclear power…” Since the start of his presidential campaign, Donald Trump has consistently emphasized his personal rapport with North Korean leader Kim Jong Un to the media, even before his visit to South Korea (ROK) for the APEC summit. Driven by a seeming desire to secure diplomatic milestones and international recognition, Trump appears to view the pursuit of a peace agreement on the Korean Peninsula as another opportunity to advance his legacy. Normal audiences might dismiss this as rhetorical flair or even as an opening for nuclear reduction. Still, such offhand recognition of North Korea’s nuclear status might lead to a precarious status on the Korean Peninsula, moving further from the shared goal of denuclearization in East Asia.
The Stepping Stone to a De Facto Nuclear State Legitimacy
Although neither the United States nor the NPT have formally recognized the DPRK as a “nuclear weapon state,” publicly calling the DPRK “sort of a nuclear power” provides the rhetorical bridge Pyongyang has sought for decades. Achieving de facto recognition as a nuclear-weapon state — however informal — has been a central strategic objective for the Kim regime. This statement could allow the Kim regime to gain more leverage for support on its nuclear arsenal in the nuclear negotiations between the United States and DPRK by arguing that “even the U.S. president acknowledges” their nuclear state terms and trying to gain more from the negotiations done without South Korea’s participation.
Compounding the problem is the current geopolitical situation in which the DPRK finds itself. Due to greater military cooperation between Russia and DPRK, Russia has opened indirect doorways to Pyongyang’s nuclear status by providing sensitive military technologies that can boost DPRK’s military capabilities. Their mutually beneficial relationship seems sustainable as Kim Jong Un stated that North Korea’s military ties with Russia will “advance non-stop,” an allusion to their future cooperation in both conventional and nuclear military technologies. With two great powers indirectly affirming and supporting its “nuclear status,” recognition can become a stepping stone to a de facto position in the nuclear order, thereby making DPRK’s nuclear program far more durable.
Undermining the US-ROK Alliance’s Extended Deterrence Credibility
Labeling the DPRK as a nuclear weapons state provides another risk to the US-ROK alliance. For decades, the U.S. extended deterrence commitment to South Korea has operated under the tacit assumption that Washington rejects a nuclear-armed DPRK and sees it as a strategic threat to both nations. Should Washington shift toward acceptance or signal flexibility on that issue, the assurance upon which Seoul relies begins to fray. At the same time, Japanese Prime Minister Sanae Takaichi stated that President Trump reaffirmed the United States’s commitment to complete denuclearization of North Korea during the US-Japan summit on October 28. This means that the United States is portraying ambiguity in its declaratory policy, thereby weakening communication and credibility, two key principles of deterrence theory. While the United States continues issuing contradictory statements, regional proliferation pressures and concerns about non-nuclear states gaining nuclear weapons capabilities mount.
Research underscores this risk. According to a 2024 study from the Asan Institute for Policy Studies, only 45.6% of the South Korean public believed the United States would use nuclear weapons in their defense in the event of a North Korean nuclear attack, and this percentage has stayed relatively consistent since 2022. Additionally, public distrust in the U.S. extended deterrence commitments persisted at 48.9% in recent years. This decline in confidence coincides with the growing support for South Korea acquiring its own nuclear weapons, where 76.2% of South Koreans agreed with Korea going nuclear, a percentage that has grown from approximately 70-71% in previous years.
The consequence of ambiguity is a drift toward defense options beyond the nuclear umbrella, more intense burden-sharing demands and a dilution of the alliance architecture that has underpinned deterrence. Thus, if the United States appears willing to tolerate a nuclear-armed DPRK, the very foundation of the US-ROK extended deterrence — its credibility and clarity — may begin to unravel, pushing South Korea toward nuclear proliferation.
Directions Ahead for Seoul
The United States and South Korea must reaffirm — rhetorically and operationally — that a nuclear North Korea should not be an endpoint to live with, but a challenge that both nations and regional actors should tackle. Both should clarify their North Korea policy and present a clear, unified message that a Complete, Verifiable, and Irreversible Denuclearization (CVID) is the ultimate goal. Simultaneously, instead of rushing into an unsustainable agreement, both nations should reinvigorate deterrence capabilities by institutionalizing nuclear consultation mechanisms, such as Nuclear Consultative Group (NCG) meetings and accelerating the Conventional and Nuclear Integration (CNI) process and training so that both have greater leverage before entering negotiations.
However, it is also crucial for South Korea to adopt a more proactive posture to strengthen its deterrence capabilities. The Trump administration’s repeated calling for greater South Korean burden sharing and United States Forces Korea’s strategic flexibility suggests a prospective redefinition of alliance responsibilities. In this environment, Seoul must prepare for a future in which the credibility of U.S. extended deterrence cannot be taken for granted. The South Korean government has already laid out plans to increase its defense spending to 3.5% of its GDP. To find a way to strengthen its autonomy, Seoul should conduct further discussions on expanding its unified command and control (C2) system for nuclear deterrence and investing heavily in C4ISR capabilities and counter-strike capabilities under the 3 Axis (Kill Chain, KAMD, KMPR) framework while further developing an independent deterrence discourse that articulates how South Korea will uphold stability amid potential U.S. withdrawal.
These efforts should also be combined with Seoul’s diplomatic efforts. Based on President Lee Jae Myung’s pragmatic foreign policy, Seoul should continue to foster trilateralism between the United States, South Korea and Japan. Since all three nations have shared national interests in managing North Korea’s nuclear ambitions, sharing a unified messaging on denuclearization amplifies the effectiveness of credibility. At the same time, strengthening trilateral coordination through deeper cooperation in theater missile defense technology, sharing early warning systems (EWS) or even establishing a trilateral extended deterrence working group will help Korea maintain interoperability and joint planning.
Overall, President Trump’s acknowledgement that North Korea is “sort of a nuclear power” is strategic signaling that Seoul should stay keen on, especially in this unpredictable diplomatic setting. Within the current geopolitical dynamic of Russian backing, Chinese acquiescence and Pyongyang’s continuous nuclear expansion, that signal matters. It is time for Seoul and Washington to rebalance rhetoric, reaffirm strong alliance guarantees and reinforce the alliance’s normative architecture.
*Editor’s note: Writing for the Center’s new Next Up in Arms Control series, SeungHwan (Shane) Kim is currently a nonresident fellow at the Indo-Pacific Studies Center. His works were published in numerous publications, including the Diplomat, the National Interest, the East Asia Forum, the Asia Times, the Pacific Forum, and more. He holds an M.A. from the Johns Hopkins School of Advanced International Studies (SAIS) and a B.A. from the University of Southern California.
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.
