We asked one of the speakers at the Pugwash / Royal Society event marking the 70th anniversary of the Russell-Einstein Manifesto, Tong Zhao, to elaborate on his remarks in writing. The article below was originally published on the Ambassador Partnership’s website.
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Efforts to reduce nuclear dangers face stiff headwinds as most nuclear armed states are increasing their reliance on nuclear weapons. At the heart of this challenge lies an intensifying rivalry among major powers, rooted not merely in strategic competition but in increasingly irreconcilable differences over basic values and norms.
The U.S.-China relationship exemplifies this troubling trend. China has established four red lines in its relationship with the United States, two of which explicitly concern ideological differences: democracy and human rights on the one hand, and China’s political system on the other. This elevation of ideological conflict to the forefront of great power rivalry, combined with territorial disputes such as those over Taiwan, has led major powers to view each other as enemies with fundamentally incompatible interests.
In such an environment, faith in diplomacy erodes. Major powers embrace a common creed— “peace through strength”—and signal that power, not persuasion, will settle disputes. The result is a world in which actors set more store by coercive capabilities than by cooperative security or international institutions, even as bodies like the UN Security Council are paralyzed by deep internal divisions.
Given this deteriorating environment, agreement on basic principles of behavior among major powers should be a priority. The escalating arms race in Asia and beyond stems largely from concerns about potential conflict over Taiwan. When states judge conflict plausible, they prepare accordingly. A foundational principle that major powers should adopt is a commitment not to use military means to change territorial status quos.
Such basic behavioral principles are precisely what is lacking in contemporary international relations. The broader international community possesses the moral authority to elevate this issue’s significance and pressure major powers to discuss and negotiate these fundamental principles, thereby reducing their dependence on military power, including nuclear weapons.
Risk reduction also demands that we confront how evolving technologies entangle nuclear and conventional operations and compress decision time. For example, the proliferation of dual-capable missiles—systems like China’s DF-26, which can carry either nuclear or conventional warheads—introduces dangerous ambiguities. In a conventional conflict, if the U.S. were to target such systems, China might misinterpret the intent as an attempt to neutralize its nuclear capabilities, prompting overreaction and escalation. This risk, initially highlighted by Western experts through workshops and publications, has gradually gained traction among Chinese counterparts, demonstrating the value of open dialogue.
Similarly, the adoption of launch-on-warning postures by the United States, Russia, and most recently China, has heightened vulnerabilities. These strategies depend on early-warning systems, including infrared satellites and ground-based radars, to detect incoming nuclear strikes and enable immediate retaliation. But with the advent of maneuvering hypersonic systems, warning data grow less definitive and inferring targets becomes less reliable. That makes early warning a foggier basis for life-and-death choices. Multilateral forums can facilitate joint recognition of such threats, even if formal agreements prove elusive. Once risks have been acknowledged, states often implement unilateral measures to mitigate them, adjusting domestic policies to enhance stability.
A key potential risk-reduction measure is the adoption of a no-first-use policy, where nuclear weapons serve solely to deter nuclear attacks by others. However, the concern of non-nuclear-weapon allies can be an obstacle to the adoption of such a policy. Japan, for instance, fears that a U.S. no-first-use pledge might embolden China’s conventional aggression. China can help to dispel such fears by providing credible conventional-level reassurances to its neighbors. Widening the conversation beyond the P5 to include affected U.S. allies and other non-nuclear states is a practical necessity for building durable support.
Civil society has a pivotal role to play in advancing the nuclear risk reduction agenda. Current risk-reduction initiatives have limited penetration in non-democratic states like China and Russia, as well as the Global South. Greater engagement with counterparts in these regions is crucial. The Global South, disproportionately vulnerable to the environmental and public health fallout from even a limited nuclear exchange (such as over the Taiwan Strait), can exert pressure on major powers to adopt responsible policies. By highlighting these impacts, non-nuclear states have a chance to hold nuclear actors accountable.
Beyond building shared understanding of specific risks posed by new technologies, scientists and policy experts can cultivate a professional ethic that prioritizes holding their governments to account, especially when it comes to nuclear weapons decisions. Too often, national expertise is channeled into critiquing foreign governments’ policies while rationalizing one’s own government’s choices. Promoting the notion that experts across nuclear-armed states must first scrutinize their own government’s nuclear policies is critical to changing internal dynamics and steering toward more constructive nuclear pathways.
In an age of sharpened rivalry, reducing nuclear risks begins with naming the dangers we share, building minimal rules to contain them, and empowering voices—especially outside the nuclear club—that can keep the major powers honest. Only then can we hope to bend today’s grim trajectory toward a safer equilibrium.
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Dr Tong Zhao is a senior fellow at the Carnegie Endowment for International Peace. He conducts research in Washington D.C. on strategic security issues, such as nuclear weapons policy, deterrence, arms control, non-proliferation, missile defence, and hypersonic weapons, and on China’s security and foreign policy. Formerly he was based in Beijing, in Carnegie’s research centre on contemporary China.