Hours before his scheduled meeting with Chinese President Xi Jinping, US President Donald Trump announced that he had instructed the Department of Defense to resume nuclear-weapons testing, ending a de facto US moratorium on explosive tests that has been held since 1992. The announcement sent shockwaves through the non-proliferation and arms-control regimes worldwide.

Shortly afterward, US Energy Secretary Chris Wright clarified that the planned tests would not include full nuclear detonations but would focus on “system tests” or “non-critical explosions” of weapon components. While this distinction limits immediate escalation, it nonetheless signals a revival of nuclear-testing activity, raising concerns among strategic analysts about the erosion of long-standing norms.

 

Can the US immediately resume nuclear testing?

Heather Williams, director of the Project on Nuclear Issues and senior fellow at the Center for Strategic and International Studies (CSIS) in Washington, DC, notes that technically the US could resume nuclear testing, but full-scale detonation would require significant preparation and infrastructure. Current plans appear focused on sub-critical or component tests, which fall short of actual explosive testing yet allow the US to validate modernized weapons systems and maintain readiness.

Williams also highlights that allegations of China and Russia conducting covert tests have circulated for years, though publicly verifiable evidence remains limited. The strategic messaging behind Trump’s announcement appears aimed less at immediate testing and more at asserting US credibility in the global nuclear hierarchy, reminding allies and rivals that Washington remains capable of technological and strategic initiative. The move raises questions about the future of the US arsenal, potential modernizations, and whether this could reignite a broader global arms competition.

 

How China and India react

China’s response was swift and cautionary. Beijing’s foreign ministry stressed that the US should honour its moratorium on nuclear testing and warned that unilateral action could “adversely affect global strategic balance and stability.” The Chinese position underscores Beijing’s concern that even non-explosive testing could erode norms and provoke a competitive spiral.

India’s reaction has been more measured but no less attentive. Though India is not a signatory to the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and last conducted nuclear tests in 1998, the announcement heightens regional anxieties about renewed nuclear competition. Analysts point out that China’s arsenal—estimated at approximately 600 warheads in 2025 and projected to reach 1,000 by 2030—is advancing qualitatively, with new missile and hypersonic capabilities. US signals regarding testing and modernization add an additional layer of uncertainty for New Delhi, which must balance deterrence, conventional defense, and strategic stability.

 

Implications for disarmament and nuclear security

Even limited, non-explosive testing carries significant implications for global nuclear norms. First, the nearly universal moratorium on explosive tests underpins the moral and strategic authority of the CTBT. While the US has not ratified the treaty, its long-standing adherence lent weight to global disarmament efforts; any reversal risks weakening this moral authority.

Second, renewed testing could accelerate arms-race dynamics. Sub-critical or system tests may provoke other nuclear powers to respond with qualitative or covert enhancements, feeding mistrust and potentially increasing the pace of strategic competition. The argument that China and Russia are already experimenting covertly, even if unproven, amplifies these pressures.

Third, verification and security risks increase. More testing, even non-explosive, places strain on global monitoring systems and may compel smaller states to hedge or accelerate indigenous capabilities. Fourth, the rationale of modernization is central: the US frames testing as necessary to validate replacement systems, echoing strategies in Russia and China and raising concerns that technical verification may once again become a measure of credibility rather than stability.

Finally, the renewed focus on testing could exacerbate a disarmament stalemate. If major powers return to testing, momentum for reductions or treaty negotiations could stall, further weakening global arms-control frameworks and increasing uncertainty in regions with nuclear-armed neighbors. In fact, Putin has already stated that Russia will take ‘reciprocal measures’.

 

Geopolitical implications for South Asia and beyond

South Asia stands at a delicate strategic juncture. India, Pakistan, and China constitute a nuclear triangle with complex interdependencies. India’s declared “no-first-use” policy and its conventional-nuclear posture are calibrated to maintain credible deterrence, but US signals on nuclear testing complicate these calculations.

China’s nuclear growth, particularly in missile technology, multiple-warhead systems, and hypersonic delivery, places additional pressure on India’s security apparatus. Reports suggesting China could achieve parity with India or exceed its nuclear capacity in the coming decade have already sharpened strategic planning in New Delhi. Pakistan, in turn, maintains its posture based on regional parity with India and benefits from Chinese support through initiatives like the China–Pakistan Economic Corridor. US signaling of potential testing further complicates South Asian deterrence dynamics, as all three powers may feel pressure to accelerate qualitative improvements or strengthen arsenals.

Nepal, as a non-nuclear state situated between China and India, is nevertheless affected by these regional dynamics. Its foreign policy has traditionally emphasized neutrality, non-alignment, and maintaining cordial ties with all neighbors. While Nepal does not possess nuclear weapons, the stability of its region directly influences its security, development, and diplomatic maneuverability. The announcement reinforces the need for Nepal and other smaller states to monitor developments, advocate for norm adherence, and support regional confidence-building measures.

The US announcement is likely to reverberate beyond South Asia. In the Middle East and on the Korean Peninsula, heightened nuclear signaling may encourage regional powers to reassess their capabilities, timelines, and reliance on extended deterrence. For US allies and partners, the signal of renewed testing raises questions about commitment, security guarantees, and the rules governing strategic behavior. Such ambiguity could complicate ongoing efforts at denuclearization talks, sanctions diplomacy, and regional confidence-building measures.

 

Conclusion

The US decision to resume nuclear-weapons testing—even in a limited, non-explosive form—represents a pivotal moment for global nuclear security. China and India face strategic dilemmas in recalibrating their deterrent postures, while the broader global order confronts potential norm erosion and renewed arms-race dynamics.

In South Asia, where nuclear competition is already tense, the consequences are especially pronounced. The episode is a reminder that in the nuclear realm, signaling is as consequential as actual weapons deployment. Whether this marks the start of renewed escalation or the stimulus for arms-control dialogue will depend not only on the superpowers but also on how regional states navigate the shifting landscape.

 

The author is a Research Director at the Nepal Institute for International Cooperation and Engagement