Nuclear weapons, largely overlooked in global discourse since the Cold War ended, are quietly re-emerging as a topic of serious debate. Four years of ongoing war in Ukraine, President Donald Trump's statements questioning continued U.S. support for NATO, the U.S.–Iran conflict now entering its second month, and growing calls for nuclear capabilities in Japan and South Korea have all fueled this resurgence.
The U.S. nuclear umbrella has long been the bedrock of security and peace in Europe and East Asia since the end of World War II. But since taking office last year, Trump has reversed Washington's traditional pro-Europe stance. He has threatened to pull the United States out of NATO — an alliance it helped create after the war — insisted that European countries must shoulder their own defense responsibilities, and even suggested bringing Greenland into America's sphere of influence. These positions have led Germany and Poland, nations long protected under the U.S. nuclear shield, to begin openly discussing the possibility of developing their own nuclear weapons.
In East Asia, China's escalating military threats toward its neighbors, combined with the Trump administration's inconsistent commitments to allied defense, have sharply increased anxiety in Japan and South Korea — both hosts to U.S. forces. Over the past two years, public voices advocating for independent nuclear arsenals have grown louder in both countries.
The New START arms reduction treaty, established between the U.S. and Russia during the Cold War, expired in February this year. The Nuclear Non-Proliferation Treaty (NPT), which entered into force in 1970, also faces mounting challenges. These international arms control frameworks have been unable to contain the resurgence of nuclear armament discourse.
U.S.–Iran Peace Talks Stall Over Nuclear Timeline
U.S.–Iran peace negotiations, mediated by Pakistan, opened last weekend but reached an impasse in the first round. The three main points of contention are Iran's nuclear program, control of the Strait of Hormuz, and war reparations. On the nuclear issue, the U.S. demands that Iran suspend uranium enrichment for 20 years, while Iran has agreed to only five years.
U.S. Vice President JD Vance, who leads the American negotiating team, said on April 14 that deep mutual distrust made it impossible to resolve everything in a single day. He stressed that Trump is not looking for a "small deal" but a comprehensive "grand bargain." According to Vance, Trump's message to Iran is clear: if it commits to abandoning nuclear weapons development, the U.S. will enable Iran to "thrive" and fully reintegrate into the global economy.
Obama Struck the Iran Nuclear Deal. Trump Walked Away — and Broke the Whole System.
The Bulletin of the Atomic Scientists has cautioned that the 2015 Iran nuclear deal — known as the JCPOA, negotiated by the Obama administration together with Britain, France, China, Russia, Germany and the European Union — was unilaterally abandoned by Trump in his first term in 2018. This decision weakened the international nuclear control system built around the NPT since 1970. The recent U.S. and Israeli strikes on Iranian nuclear facilities have set a dangerous precedent, prompting questions about whether other powers such as China or Russia might one day take similar unilateral action against countries they suspect of developing nuclear weapons.
76% of South Koreans Now Want the Bomb — a Record High
The shift in public opinion is striking even in countries where nuclear weapons have long been considered taboo. In South Korea, a report released last year by the Asan Institute for Policy Studies found that 76 percent of respondents support the development of an independent nuclear arsenal — up from 70.9 percent in 2024 and the highest level ever recorded.
Wang Hung-jen, Executive Director of the Institute for National Policy Research and professor of political science at National Cheng Kung University, attributes the surge to several converging pressures: the persistent military threat from North Korea, trilateral military cooperation among China, North Korea and Russia, and growing public doubts about the reliability of the U.S. nuclear umbrella.
During his visit to South Korea last October, Trump announced plans to share nuclear submarine technology with Seoul. However, reports emerged in March that the U.S. Department of Energy had placed South Korea on its "sensitive countries list," tightening oversight on access to U.S. nuclear technology and expertise. Wang noted that this reflects internal divisions within the U.S. government and that any actual technology transfer remains uncertain. He added that the road from public discussion to actual possession of nuclear weapons is long and filled with high barriers.
Japan Has Held Its Non-Nuclear Principles for 60 Years. That May Be About to Change.
A similar softening of long-held positions is underway in Japan, the only country in the world to have suffered nuclear attack. According to the Asahi Shimbun, a senior security policy official in the prime minister's office privately told reporters last December that Japan should begin discussing nuclear weapons options, citing the severe regional security environment and doubts about the credibility of the U.S. nuclear umbrella. The remarks sparked an immediate public backlash, and Chief Cabinet Secretary Kihara Minoru quickly reaffirmed that Japan's non-nuclear policy remains unchanged.
Wang pointed out that Japan's "three non-nuclear principles" — no possession, no production, and no introduction of nuclear weapons — were established by Prime Minister Eisaku Sato in 1967 and have guided national policy for nearly 60 years. Under Prime Minister Sanae Takaichi, however, there is now discussion about possibly revising the "no introduction" principle to permit nuclear sharing with the United States under specific conditions. While this falls short of developing an independent nuclear arsenal, Wang described it as a significant step forward given Japan's current constraints.
Taiwan Can't Go Nuclear. Here's What It Can Do Instead.
Taiwan itself cannot realistically pursue nuclear weapons under present circumstances. Asked how Taipei should respond to the rising international debate on nuclear armament, Wang recommended that Taiwan consider embedding its core interests within the strategic interests of the United States, Japan, the Philippines and other partners.
For instance, by making the case that preventing instability or escalation in the Taiwan Strait would help avert a nuclear arms race across East Asia, Taiwan could encourage these countries to provide support on multiple levels to stabilize the situation and strengthen deterrence.
The 2026 NPT Review Conference: A Make-or-Break Moment for Nuclear Order
The 2026 NPT Review Conference will take place at the United Nations from April 27 to May 22. Issues stemming from the Iran conflict — particularly its nuclear program — will be a major focus among the 191 member states. The gathering will serve as an important test of whether the NPT can still prevent a new wave of global nuclear proliferation.
The Economist has reported that once a nuclear arms race gains momentum, it could become extremely difficult to stop. On a more optimistic note, any country that takes the first step would face enormous costs, while so-called rogue states caught developing nuclear capabilities would likely encounter severe economic sanctions and the threat of military action. Violating the NPT could also isolate a country internationally, imposing heavy economic and diplomatic burdens.
At present, among recognized nuclear powers, India, Pakistan and Israel are not NPT signatories, and North Korea withdrew from the treaty in 2003. Whether the global nuclear governance system established since the Cold War can withstand the pressures of the unresolved conflicts in Ukraine and Iran remains an open question that only time will answer.
