Annual Consensus Statement: Second Track Nuclear Dialogue in Europe

Key Chapter Title List

1. National Policy, Alliance Management, and Extended Deterrence
2. Modernization and Integrated Air and Missile Defense
3. Arms Control and Non-Proliferation
4. Addressing Challenges in a Dynamic Security Environment

Document Introduction

This document is a consensus statement issued following the 2025 meeting of the U.S.-U.K.-France Trilateral Track II Nuclear Dialogue, organized by the Center for Strategic and International Studies (CSIS) in partnership with the Royal United Services Institute (RUSI) and the Fondation pour la Recherche Stratégique (FRS). Launched in 2009, this dialogue mechanism brings together former senior officials and renowned experts and scholars from the United States, the United Kingdom, and France. It aims to conduct in-depth discussions on issues such as nuclear deterrence, arms control, and non-proliferation policies, to identify areas of common concern and seek consensus, thereby strengthening trilateral cooperation in addressing complex nuclear policy challenges. Senior incumbent officials from the three countries also regularly participate in the discussions. All signatories to this statement have expressed their agreement in their personal capacities.

Currently, as the only three nuclear-weapon states within the NATO alliance, the United States, the United Kingdom, and France share common values and goals in maintaining global peace and security and acting as responsible stewards of the nuclear order. Although the three countries hold unique perspectives and policies on nuclear issues and the nature of today's security environment, they play a distinctive and enduring role in sustaining international alliances and partnerships, particularly in matters of nuclear deterrence, non-proliferation, and arms control.

At the level of national policy and alliance management, the July 2025 "Northwood Declaration" marked a historic and positive step forward in U.K.-France nuclear cooperation, laying the cornerstone for both nations to play a stronger role in European security. Practical coordination on deterrence policy between London and Paris is expected to enhance the efficiency of P3 cooperation and signal to external parties that NATO's two European nuclear powers are preparing to address the challenges of the current security environment, while maintaining independent decision-making centers to increase adversary uncertainty and strengthen European deterrence. These policy changes, alongside significant defense acquisitions such as the U.K.'s decision to procure nuclear-capable F-35A aircraft and rejoin NATO's Dual-Capable Aircraft (DCA) mission, demonstrate the commitment of the U.K. and France to strengthening NATO's overall nuclear deterrence. The relevant cooperation aims to complement, not replace, the United States' extended nuclear deterrence in Europe. Simultaneously, the United States should continue to advance the modernization of its existing nuclear arsenal and, leveraging the evident high degree of consensus within Congress, ensure that the recommendations of the 2023 Strategic Posture Commission and the 2024 Defense Committee yield results, achieving tangible progress in force modernization and scale growth. Facing multipolar competition, the alliance needs to manage and redistribute burdens, and the United States should welcome and encourage deeper policy and capability coordination in Europe.

In the field of modernization and integrated air and missile defense, the ongoing Russia-Ukraine war continues to highlight the transformative role of long-range precision strike capabilities and missile defense in modern conflict. Europe and the United States are making significant investments through the European Sky Shield Initiative and Project Gold Dome, respectively. Although homeland missile defense in Europe and the United States faces different challenges requiring distinct solutions, ongoing collaboration among the P3 nations will enhance the efficiency of scaling missile defense system deployments and their post-deployment effectiveness. Ally participation is a cornerstone of Project Gold Dome, and the United States should avoid raising concerns among allies that the project's development might lead to a U.S. retreat from other alliance commitments. Large-scale missile defense is costly, and burden-sharing in areas such as technology development can alleviate ally concerns and strengthen alliance cohesion. All three countries are advancing modernization programs for their nuclear deterrent forces, including France's deployment of the M51.3 submarine-launched ballistic missile and modernization of the ASMPA-R air-launched cruise missile, the U.K.'s plan to rejoin the NATO DCA mission, and the United States' comprehensive advancement of nuclear force modernization, including enhanced theater nuclear capabilities. Sustained modernization is crucial to ensuring adequate extended deterrence coverage, maintaining independent and credible decision-making centers vis-à-vis adversaries, and providing the P3 with flexible options for managing escalation across multiple theaters and domains.

In the area of arms control and non-proliferation, although the P3 nations remain willing and prepared to engage in sincere arms control dialogue when conditions are ripe, Russia and China appear to lack interest in participating in genuine arms control measures for the foreseeable future. Russia's violations of the New START Treaty provisions (including suspending participation where the treaty has no such stipulation) and its violations of the INF Treaty demonstrate that it does not take arms control seriously; any proposals from Russia should be viewed with high skepticism. Similarly, Russia and China show little willingness to engage in positive cooperation with other P5 members (France, the U.K., the U.S.) on non-proliferation issues. In fact, adversaries' resistance to U.S. extended deterrence—a fundamental tool for preventing ally proliferation—suggests that Russia and China may now prioritize non-proliferation less than in the past, based on their own interests.

The impending disappearance of meaningful strategic arms control, the waning interest in non-proliferation cooperation within the P5, and the uncertainty surrounding Iran's nuclear program will converge at the April 2026 Nuclear Non-Proliferation Treaty (NPT) Review Conference. The P3 should demonstrate continued unity and commitment to the NPT in 2026, while ensuring they derive corresponding value from the treaty, the Review Conference, and the P5 process. Ahead of the April meeting, the P3 should work to counter disinformation regarding extended deterrence and nuclear sharing and develop a more ambitious agenda for the ongoing P5 process, including sustained progress on doctrinal transparency and maintaining networks of young professionals. This work becomes particularly important on the eve of the critical 2026 Review Conference.

Finally, in the face of a dynamic security environment, adversaries continue to seek to undermine P3 collaboration, divide the NATO alliance, and develop new capabilities designed to offset NATO's advantages and defensive capabilities across various conflicts. The P3 nations must jointly address these challenges through sustained, close dialogue and coordination to maintain alliance solidarity and strategic stability.