Variable 3: Preventing Nuclear War

The world is living through its most dangerous moment in decades, on the verge of a renewed arms race, with the threat of nuclear war at its highest since the Cold War. Increased reliance on nuclear weapons for security remains both a source and symptom of heightened great power tension. Averting nuclear war — a moral imperative — requires restraint and de-escalation among great powers in the conventional and nuclear realms, including reducing the risk of military clashes between nuclear-armed states. 

Averting nuclear war — a moral imperative — requires restraint and de-escalation among great powers in the conventional and nuclear realms.

A new nuclear arms race creates incentives that run counter to nuclear non-proliferation and disarmament obligations under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). By doubling down and recommitting to nuclear weapons within their security strategies, nuclear weapon states (NWS) increase the value attached to them, encouraging their pursuit and acquisition by non-nuclear weapon states (NNWS). Without tangible progress toward nuclear disarmament, the shared non-proliferation obligations underpinning the NPT are at risk of shattering. Preventing nuclear war is not merely an agenda to manage — it is an existential imperative. 

The NPT’s five recognized nuclear weapon states (hereafter, the N5) are responsible for upholding international peace and security as permanent members of the U.N. Security Council. They must make far-reaching strides toward nuclear disarmament to preserve the NPT and oversee its full and effective implementation, including the legal obligation to engage in and conclude nuclear disarmament negotiations under Article VI. The recent entry into force of the Treaty on the Prohibition of Nuclear Weapons reveals the extent to which NNWS remain committed to the disarmament agenda.

…states should take steps toward eliminating plans for short-notice preemptive nuclear strikes and launch-on-warning options from nuclear doctrines and postures as part of a significant “de-alerting” effort.

In conjunction with diplomatic efforts to improve political relations between all nuclear-armed states — including by strengthening conventional arms control, pursuing military deconfliction, and remaining attentive to one another’s core interests — reducing great powers’ reliance on nuclear weapons will reduce one of the greatest threats to humanity. In support of U.N. Secretary-General Antonio Guterres’ New Agenda for Peace and Our Common Agenda, the following recommendations provide practical ways of supporting and implementing nuclear risk reduction and disarmament obligations before it is too late. 

Proposal 6: Preventing the accidental use of nuclear weapons

The new risks presented by emerging technologies destabilize the deterrence landscape. The serious risks of accidental nuclear launch stemming from maintaining nuclear forces at the high levels of operational readiness familiar from Cold War nuclear postures are augmented today by new risks of cyberattacks on nuclear command and control. States should undertake several measures over the coming years in pursuit of nuclear disarmament and non-proliferation obligations and to enhance crisis stability, which could allow nuclear powers to “de-alert” existing nuclear forces without undermining deterrence in the interim or increasing incentives for a conventional war. Such steps would be in line with previous U.N. First Committee and General Assembly resolutions, most recently in 2020, to “decrease the operational readiness of nuclear weapons systems” — an effort supported by almost every state, including several nuclear-armed states party and not party to the NPT.¹

• De-alerting: Alongside efforts to strengthen conventional arms control and improve political relations between great powers (including the measures proposed in other sections of this report), states should take steps toward eliminating plans for short-notice preemptive nuclear strikes and launch-on-warning options from nuclear doctrines and postures as part of a significant “de-alerting” effort. These steps can minimize the chance of military clashes among nuclear-armed states.
  • More ambitious de-alerting steps could include storing nuclear warheads separate from their missiles, disabling some missiles and launch systems, and placing warheads under civilian control. However, this would require a qualitative change of relations among great powers, a movement from relations based on deterrence to relations based on mutual trust, cooperation, and even partnership. 

• No cyberattacks on NC3: Nuclear weapon states should jointly pledge to avoid cyberattacks against other states’ nuclear command and control systems (NC3). Eventually, this should lead to an agreement prohibiting attacks on nuclear command and control systems via cyberspace or missile or drone strikes, including by conventional means.

• Evaluating artificial intelligence (AI) risks: Nuclear-armed states should initiate and forge a comprehensive framework, developed through collaborative and inclusive dialogues among NWS and NNWS, to evaluate the risks of integrating AI into NC3 systems. States should agree upon baseline definitions, norms, and unilateral declarations and actions, as well as confidence-building measures with respect to the use of emerging technologies in NC3 systems. Such measures should lead to longer-term, more formal arms control and risk reduction arrangements.

• “Human in the loop:” Building on this integrated risk assessment of AI in nuclear command and control, nuclear weapon states should each unilaterally declare that they will not place their NC3 systems under full command of AI.
  • NWS should share and clarify their definitions and understandings of keeping a “human in the loop,” especially with respect to integrating higher-risk AI models into their NC3 systems, including cutting-edge deep-learning models.

Proposal 7: Preventing the deliberate use of nuclear weapons

The N5’s January 2022 statement that a “nuclear war cannot be won and must never be fought” was an important positive step. The N5 should reaffirm this statement and build upon it with tangible risk-reduction efforts and confidence-building measures to restore dialogue, with the goal of avoiding direct military clashes among nuclear weapons states. This would allow them to reduce the role of nuclear weapons in their national security strategies.

• No-first-use agreement: As soon as possible, states should begin discussions on what a credible multilateral no-first-use agreement would look like and what initial reciprocal measures would be necessary to make such an agreement possible, considering the implications it may have for NWS allies. As part of this endeavor, nuclear weapon states should renounce attempts to threaten one another’s vital interests and those of allied states through non-nuclear wars and, so long as they retain possession of nuclear arsenals and this prior condition is respected, commit not to be the first to use nuclear weapons against another state.² They would also promise not to threaten to use nuclear weapons against non-nuclear weapon states.
  • Such a declaratory policy should make clear that it is in the service of reducing the role of nuclear weapons within states’ security strategies in compliance with all existing treaty obligations. 

• Recommitting to negative security assurances: Nuclear-armed states should also recommit to — and expand upon — their existing commitments to eschew nuclear threats under unilateral negative security assurances, particularly with respect to nuclear weapons free zone treaties.
  • States should also work toward a universal and legally binding instrument to assure NNWS, particularly those within nuclear-weapon-free zones (NWFZs), against the use or threat of use of nuclear weapons.

• Arms reductions: Building on risk reduction efforts, NWS should make strides to negotiate limits and reductions of nuclear and conventional arsenals. 

• Transparency: As another interim risk reduction measure, NWS should commit to increased transparency regarding their existing nuclear capabilities, doctrines, and modernization plans. This could take place through the N5’s ongoing dialogue on nuclear doctrines or through the draft reporting form offered by the Nonproliferation and Disarmament Initiative in 2012 and 2017. 

• Commitments: The international community, particularly leading non-nuclear and non-aligned states, should pressure NWS to take the necessary measures that would allow them to:
  • Not further increase their nuclear arsenals and develop clear plans for their reduction;
  • Not produce fissile material for nuclear weapons or other nuclear explosive devices;
  • Not design new weapons;
  • Not deploy nuclear weapons on their territory, another state’s territory, or in outer space;
  • Not conduct nuclear tests; and
  • Not threaten to use nuclear weapons.
  • A U.N. Security Council resolution should formalize these commitments. 

Proposal 8: Revitalizing the global commitment to nuclear disarmament

The majority of U.N. member states have rejected nuclear weapons by joining the NPT as non-nuclear weapon states, creating NWFZs and, most recently, by bringing into force the Treaty on the Prohibition of Nuclear Weapons. Most countries in Latin America, Africa, the Middle East, and Southeast Asia view nuclear deterrence as anathema to national security and inherently dangerous to humanity. The following measures should be pursued to build on this further:

• Strengthening the NPT: All NPT states should recommit to seeking the full and effective implementation of the NPT, including its Article VI obligations on nuclear disarmament. Drawing on some of the suggestions put forth by civil society,NPT states should bolster and protect the base nuclear nonproliferation and disarmament commitments underpinning the NPT and commit to strengthening the NPT Review Process through procedural and substantive changes.³  

• Revitalize the U.N. Disarmament Machinery: In addition to strengthening and reforming the NPT Process, there is also a need to reform existing multilateral disarmament fora. Through a Special Session of the General Assembly devoted to Disarmament, states should take up a serious review of the functioning of nuclear disarmament machinery, including the Conference on Disarmament, the U.N. Disarmament Commission, and the First Committee on Disarmament and International Security, among others.⁴ This review could include a review of the mandate and rules of procedure, including the role of the presidency, civil society participation, composition, and observers.  

Suggested measures to reduce the risk of nuclear war

Effects and consequences of nuclear use: Today, even more than in the Cold War, a major nuclear conflict could escalate from a single miscommunication or blunder and extend far beyond the immediate areas and the people initially impacted. In this context, we welcome the U.N. General Assembly’s current efforts to renew study on the effects of nuclear use. To increase even further the international community’s appreciation of the heightened risk of nuclear weapons use, as well as to increase scientific understanding of the comprehensive suite of the effects of nuclear exchanges of different sizes, we advise the General Assembly to adopt a resolution that mandates a comprehensive study of the consequences of nuclear detonations in the twenty-first century every five to seven years. This recurring study would incorporate the effects of blasts of various yields, radiation sickness, displacement, migration, effects on critical infrastructure and supply chains, and the risk of starvation and famine due to long-term effects on climate, agricultural production, and global food markets.⁵ While such a study would not, on its own, correct the great powers’ current perception that their core interests are at risk, it would nonetheless serve to revitalize popular and elite-level awareness of the stakes and risks of nuclear war in the twenty-first century.

1. United Nations, “Decreasing the operational readiness of nuclear weapons systems : resolution / adopted by the General Assembly,” UN General Assembly, A/RES/75/72, December 17, 2020, https://digitallibrary.un.org/record/3895585?ln=en&v=pdf. ↩︎
2. Though U.S. leaders have vacillated in years past on a sole-purpose declaratory policy, the increasing U.S. desire to engage China in nuclear talks will require substantive consideration of this issue. Steve Andreasen, Declaratory Policy: Advancing Sole Purpose, NTI Paper, https://media.nti.org/documents/Declaratory_Policy_Advancing_Sole_Purpose_-_Andreasen_Excerpt.pdf; and W.J. Hennigan, “The U.S. Has Received a Rare Invitation From China. There Is Only One Right Answer,” The New York Times, April 15, 2024, https://www.nytimes.com/2024/04/15/opinion/china-nuclear-weapons.html. ↩︎
3. Thomas Markram and Gaukhar Mukhatzhanova, “Further Strengthening the NPT Review Process: Reflections and Recommendations,” Vienna Center for Disarmament and Non-Proliferation (May 2023), https://vcdnp.org/further-strengthening-npt-review-process/. ↩︎
4. The U.N. General Assembly has held three Special Sessions devoted to Disarmament (SSOD). There was SSOD-I in 1978, SSOD-II in 1982, and SSOD-III in 1988. United Nations, “Special Sessions of the General Assembly devoted to Disarmament,” UN Office of Disarmament Affairs, webpage, https://disarmament.unoda.org/topics/ssod/. ↩︎
5. The idea of a study of this variety was first advanced in “Report of the Scientific Advisory Group on the Status and Developments Regarding Nuclear Weapons, Nuclear Weapon Risks, the Humanitarian Consequences of Nuclear Weapons, Nuclear Disarmament, and Related Issues,” TPNW/MSP/2023/8, October 27, 2023: 24. https://front.un-arm.org/publications/tpnw-sag-report.pdf. ↩︎