Trilateral Track II Nuclear Dialogue Consensus Statement of 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 report is a consensus statement achieved in 2025 through 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 and the Fondation pour la Recherche Stratégique. Launched in 2009, this dialogue mechanism brings together senior nuclear policy experts from the United States, the United Kingdom, and France (the P3 nations), including former senior government officials and prominent scholars. 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 collaboration in addressing complex nuclear policy challenges. Senior officials from the current governments of the three nations also regularly participate in the discussions. This statement reflects the collective assessment of emerging strategic challenges facing the P3 nations from the 2025 dialogue.

The report first focuses on national policy, alliance management, and extended deterrence. The July 2025 "Northwood Declaration" is viewed as a historic step forward in U.K.-France nuclear cooperation, laying the groundwork for both nations to play a stronger role in European security. Practical coordination on deterrence policies between the U.K. and France is expected to enhance the efficiency of P3 cooperation and demonstrate to external parties that the two European nuclear powers within NATO are actively preparing to address current security challenges, while maintaining independent decision-making centers to increase adversary uncertainty and strengthen European deterrence. Such policy adjustments, alongside significant arms procurements such as the U.K.'s decision to acquire nuclear-capable F-35A aircraft and join NATO's Dual-Capable Aircraft mission, signal that London and Paris are taking action to bolster NATO's overall nuclear deterrence. The report emphasizes that U.K.-France cooperation aims to complement, not replace, U.S. extended nuclear deterrence in Europe. The United States should welcome and encourage deeper European policy and capability coordination to manage and redistribute alliance responsibilities in a multipolar competitive landscape. Simultaneously, the report notes that the U.S. should continue advancing its existing arsenal modernization and leverage the high degree of consensus within Congress to ensure tangible outcomes from the recommendations of the 2023 Strategic Posture Commission and the 2024 Defense Committee. The report warns that partisan divisions and political challenges within the United States could hinder necessary yet ambitious nuclear modernization plans.

In the area of modernization and integrated air and missile defense, the report points out that 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 in missile defense through the European Sky Shield Initiative and the Golden Dome program, respectively. Although European and U.S. homeland missile defense face distinct problems requiring different solutions, sustained cooperation among the P3 nations will enhance the efficiency of scaling missile defense system deployments and their post-deployment effectiveness. The report specifically notes that the Golden Dome project is based on allied participation, and the U.S. should avoid raising concerns among allies that the program's development might lead to a U.S. retreat from other alliance commitments. Large-scale missile defense is costly, and burden-sharing in areas like technology development can help alleviate ally concerns and strengthen alliance cohesion. Furthermore, the report outlines the respective nuclear force modernization processes of the P3 nations and emphasizes that continued modernization is crucial to ensuring adequate extended deterrence coverage, maintaining independent credible decision-making centers, and providing the P3 nations with flexible options for managing escalation in multi-theater, multi-domain conflicts.

Regarding arms control and non-proliferation, the report argues that while the P3 nations are willing and prepared to engage in arms control in good faith when conditions are ripe, Russia and China appear to lack interest in participating in genuine arms control measures in the near term. Russia's violations of the New START treaty provisions (including suspending participation without treaty basis) and its violations of the INF Treaty indicate it does not take arms control seriously, and any proposals from it should be viewed with high skepticism. Similarly, Russia and China show little willingness to actively cooperate with other P5 members (i.e., France, the U.K., and the U.S.) on non-proliferation issues. Adversary resistance to U.S. extended deterrence—a fundamental tool for preventing ally proliferation—even suggests that Russia and China may currently prioritize non-proliferation less than in the past, based on their own interests. The report notes that the impending disappearance of meaningful strategic arms control, waning interest in P5 non-proliferation cooperation, and uncertainties surrounding Iran's nuclear program will converge at the April 2026 Nuclear Non-Proliferation Treaty (NPT) Review Conference. The P3 nations 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. Before the April meeting, the P3 nations should work to counter disinformation regarding extended deterrence and nuclear sharing and develop a more ambitious agenda for the ongoing P5 process.

Finally, the report emphasizes that the P3 nations are facing a dynamically changing security environment. Adversaries continuously seek to undermine P3 collaboration, divide the NATO alliance, and develop new capabilities aimed at offsetting NATO's advantages and defensive capabilities across various conflicts. In this context, sustained dialogue and collaboration are more critical than ever. The P3 nations need to jointly support a realistic and manageable path to ending the war in Ukraine, while encouraging a strengthened deterrence posture in other parts of Europe, and commit to better communicating to the public the threat posed by Russia and the paramount importance of NATO's effective conventional and nuclear deterrence, in order to address the nuclear perception gap within the alliance.