The Art of the Possible: The Future of the P5 Process On Nuclear Weapons

October 2014

By Andrea Berger and Malcolm Chalmers

In 2007 the five recognized nuclear-weapon states convened for the first time to examine what nuclear transparency and confidence-building measures they could jointly pursue. The P5 process,[1] as it came to be known, was born in a nuclear policy environment vastly different from the one that prevails today.

It was established as a result of an initiative from the United Kingdom, which was eager to reverse the stagnation it sensed in the nuclear-weapon states’ progress toward meeting their disarmament commitments under the nuclear Nonproliferation Treaty (NPT). In June 2007, UK Foreign Secretary Margaret Beckett argued for the need to “engage with other members of the P5 on transparency and confidence-building measures,” as well as to involve them in the testing of future verification regimes.[2] 

The French submarine Le Terrible is seen during its inauguration in Cherbourg on March 21, 2008. In his speech at the ceremony, French President Nicolas Sarkozy highlighted France’s efforts to increase transparency with regard to its nuclear weapons program and dismantle its facilities for producing nuclear weapons material. (Mychele Daniau/AFP/Getty Images)This initiative aligned with renewed interest in arms control and nuclear transparency measures in other nuclear-weapon states. French President Nicolas Sarkozy used his 2008 speech at Cherbourg to reveal new transparency measures for the French nuclear force.[3] Shortly after entering office in 2009, U.S. President Barack Obama set out his commitment to work toward a world free of nuclear weapons. He promised to reach an agreement with Russia on a further round of strategic arms reductions by the end of 2009 and argued that this would “set the stage for further cuts” and that the United States would seek to include all the nuclear-weapon states in this effort.[4] 

The P5 process was launched at approximately the same time, and its first high-level conference took place in London in September 2009. Its value in the broader strategic context was clear, that a forum for multilateral confidence-building measures among the nuclear-weapon states in relation to their nuclear forces could support other bilateral and multilateral nuclear initiatives, in which there was fresh interest. Proponents of the process hoped that nuclear-weapon-state cooperation could gradually generate sustainable momentum toward further disarmament. 

These encouraging developments breathed new life into the 2010 NPT Review Conference, at which the participating countries unanimously agreed on a 64-point action plan covering all three of the treaty’s pillars—disarmament, nonproliferation, and peaceful uses of nuclear energy. Of particular relevance to this discussion, the action plan called on the nuclear-weapon states to act together to reduce the number and role of nuclear weapons and to enhance transparency and mutual confidence. With this validation, the P5 process accelerated its efforts to undertake collaborative projects in time for the 2015 review conference. 

The P5 process is now nearing that milestone. Over the course of its life, it has taken small but potentially important collective steps. The modesty of these steps, however, has made a number of non-nuclear-weapon states concerned that earlier promises, namely, that the P5 process would someday help facilitate new disarmament measures, may never come to pass. Instead of gradual progress, those states see only opacity and potentially insurmountable stagnation. 

This impression is reinforced by the changes in relations among the nuclear-weapon states that have taken place over the past five years. These changes, such as those arising from the recent conflict over the future of Ukraine, have occurred outside of NPT meeting rooms. Antagonism of the type generated by the crisis in Ukraine is something the P5 process never had the power to counter. At the moment, the process is in a difficult position, caught between strategic realities and NPT pressures. 

It might still be possible for the P5 process to continue to undertake new initiatives, even if they are small and lack buy-in from all five members of the group. By doing so, the process could help lay the groundwork for more-ambitious disarmament endeavors that might become palatable if security relations among the nuclear-weapon states begin to improve. At the 2015 NPT Review Conference, these states should demonstrate the P5 process’ continued relevance by setting out a work plan detailing the initiatives they will pursue in the next NPT review cycle. Even this objective might be a challenge, given the reluctance of some nuclear-weapon states to support forward movement. Yet, without such a plan, doubts about the purpose of the process are likely to grow further, expanding the pressures that the five countries are likely to face from non-nuclear-weapon states in the NPT environment. 

The First Frost

As the 2015 review conference approaches, the broad international context is likely to be very different from that of 2010. Strategic relations between Russia and the Western powers have worsened to a level not seen since the late 1980s. Prospects for further strategic force reductions, through a successor to the New Strategic Arms Reduction Treaty (New START), have long since receded. Even existing treaties, notably the Intermediate-Range Nuclear Forces Treaty, are coming under pressure. 

Prospects for progress on other disarmament elements of the NPT action plan also have dwindled. The initial hope of the Obama administration that it might be able to resubmit the Comprehensive Test Ban Treaty (CTBT) to the Senate for approval, still a real prospect in 2010, has been dashed by the intransigence of Senate Republicans. The agreement to convene a conference on a zone free of weapons of mass destruction in the Middle East by 2012, a key element of the 2010 review conference consensus, may go unrealized even by mid-2015. 

With almost every other disarmament track from the action plan in disarray or stasis, the P5 process has been left as one of the few remaining, albeit not untroubled, vestiges of the high hopes with which the participants in the 2010 review conference agreed to its final document. As a result, the process is now at risk of carrying a weight of expectations that exceeds the important but essentially supportive role it was intended to play. In the context of discussions among NPT-focused diplomats, it can sometimes appear as if the main obstacle to further progress on the P5 process or on disarmament more widely is the tension between forward-pushing non-nuclear-weapon states and resistant nuclear-weapon states. Although these tensions are undoubtedly present, the main obstacles to progress on the process, as on most other elements of the disarmament agenda, lie between the nuclear-weapon states themselves. The common interest in developing cooperative arms control measures is increasingly being outweighed by calculation of competitive military and political advantage, thereby narrowing the opportunities for progress to be made.

With the bilateral and multilateral disarmament and arms control tracks having now stalled, the P5 process, embedded in the NPT context but composed of states that developed and maintain nuclear weapons partly in reaction to insecurity created by the other members of the group, finds itself in a difficult position. In one respect at least, the five nuclear-weapon states remain united. They all share legal obligations within the NPT and the agreements reached at the 1995 NPT Review and Extension Conference and subsequent review conferences to act together. The 2010 action plan, to which the five nuclear-weapon states agreed, reinforces this. 

At present, the nuclear-weapon states still share an interest in being seen to be taking this obligation seriously, not least to distinguish themselves from the “unrecognized” nuclear-armed states outside the NPT. As a result, none of the five has yet thought it in its interest to abandon the P5 process unilaterally despite their differences. Regardless of growing strategic tensions among some nuclear-weapon states, the P5 process must therefore also remain attentive to the concerns of non-nuclear-weapon states and continue to search for new forms of disarmament-relevant cooperation. Yet, with the process having only produced small fruit, NPT discussions in the run-up to the 2015 review conference are rife with discontent. 

Progress So Far

Efforts in the P5 process over the past five years have been focused on three areas: development of a glossary of nuclear terms, improvements in verification and monitoring, and the development of transparency and common reporting measures. 

Glossary. The initiative to produce a common glossary of nuclear terms is the most substantive element in the group’s work plan. At the beginning of the process, the participants realized that further discussions on transparency and arms control could be hampered unless there was a common understanding of terminology. At the first meeting, therefore, the five states agreed to develop a glossary of nuclear terms. China later agreed to lead this initiative.

By early 2013, the group had agreed on a short list of around 200 to 300 terms in English. It then proceeded with the more challenging task of negotiating common definitions for them. Recently, however, the glossary process appears to have fallen behind schedule as a result of unspecified substantive disputes. It is hoped that forthcoming meetings of the experts working group can resolve any outstanding issues and the process of translation into Chinese, French, and Russian can begin.[5] Fortunately, China continues to express its intention to submit a first draft of a glossary to the 2015 review conference. It is highly likely that a glossary, perhaps minus any divisive terms, will be presented at that event. 

One key factor in assessing the initial success on the glossary strand of the process will be whether it has produced common definitions of terms on which there is not already agreement in other multilateral glossaries, such as that maintained by the International Atomic Energy Agency. A second important factor will be whether it is able to produce terms that are relevant for future transparency and disarmament processes, such as “nuclear warhead” or “strategic missile.” If the glossary produces nothing new in these areas after five years of work, skepticism as to the value of the process could grow. Inevitably, there will be some areas in which consensus will not be possible and more work will be needed. In order to gain support for the further development of the process, however, negotiators need to show some concrete results from their first round of work. 

Verification and monitoring. The development of approaches to verifying and monitoring compliance with existing and future arms control treaties is already an important element in U.S.-Russian nuclear limitation regimes. It is likely to be of even greater importance if the numbers of weapons are reduced further or more states take on obligations to limit the size or shape of their arsenals. 

As a result of this logic, ever since its 1998 “Strategic Defence Review,” the UK has devoted some resources to exploring the technical requirements for verifying nuclear disarmament, with a particular focus on warhead dismantlement. To the irritation of some other nuclear-weapon states who wish to avoid involving their non-nuclear-weapon counterparts in verification initiatives, the UK has been cooperating with Norway on joint warhead dismantlement verification research since 2007. In October 2013, the UK and the United States revealed for the first time that they had been conducting similar research for more than a decade.[6] The UK has publicly declared its interest in exploring opportunities for collaboration with China on verification, and the two sides reportedly are now discussing the possibility. Beyond these largely bilateral initiatives, however, the five nuclear-weapon states have done little work together on the subject. 

Multilaterally, technical experts from the five states convened in London in 2012 for a meeting on verification issues and again in Vienna in March 2013 with respect to CTBT support. The group also has announced its intention to provide assistance to the field exercise that the Comprehensive Test Ban Treaty Organization (CTBTO) is scheduled to hold in Jordan in November and December. 

Transparency and common reporting. Although verification of current data is off the agenda of the P5 process, there has been some progress on nuclear transparency, defined in this context as the publication of unverified information for the purposes of building confidence among the nuclear-weapon states and demonstrating NPT compliance to non-nuclear-weapon states. Progress on nuclear transparency was one of the priorities laid out in the 2010 action plan. Various items of the action plan call on the nuclear-weapon states to work toward qualitatively and quantitatively reducing their arsenals and report on their progress to the 2014 Preparatory Committee meeting for the 2015 NPT conference (Action 5), report regularly on action plan implementation (Action 20), and produce a standard reporting template into which transparency data could be entered, facilitating comparison among national declarations (Action 21). 

Pang Sen, director-general of the Arms Control and Disarmament Department in the Chinese Foreign Ministry,  speaks during a press conference at the UN Office at Geneva on April 19, 2013, following a two-day meeting of the five nuclear-weapon states.The nuclear-weapon states reached agreement on such a framework and presented their results to the NPT preparatory meeting earlier this year. They asserted that this submission fulfilled their obligations under Actions 5, 20, and 21. Yet, the common headings agreed by the five for the reporting framework were so general as to have been of little value in building confidence.[7] This reflects different national approaches to nuclear transparency among the five nuclear-weapon states and an overarching unwillingness at present to modify them substantially. Since 2010, France, the UK, and the United States have been willing to publish some aggregate information on their holdings of nuclear weapons and strategic delivery vehicles. By contrast, China and Russia have not been willing to do so. 

The five documents did have some common substantive characteristics. Each provided some useful insight into the nuclear doctrine and arms control policy of the country that submitted it. Indeed, China concentrated almost exclusively on this subject in its disarmament section and excluded any details on the shape or size of its arsenal. On the whole, the five reports provide little new data, for example, on warhead or delivery vehicle numbers.[8] 

Some disarmament-oriented non-nuclear-weapon states said the reporting exercise, despite the well-worn content and flaws in delivery, was a good start. It was apparent that many of these states believe that this start had taken place only because of the inclusion of a deadline in the action plan. It is now widely expected that the nuclear-weapon states will repeat this exercise, at a minimum once every review cycle. One can expect the need for this commitment and what specifically it would mean to be a point of debate at the 2015 review conference. Should future iterations of the common reporting exercise take place, the nuclear-weapon states will be expected to provide new data as evidence of forward movement. Yet, the five countries are still some way from reaching consensus on a reporting framework that would replicate, even on an unverified and partial basis, the publicly available information exchange already taking place between Russia and the United States under New START. 

Creating a Road Map 

Limited movement in the P5 process over the past year has followed predictable but positive trajectories. The five nuclear-weapon states continued to brief one another on bilateral verification efforts, highlighting the possibility that bilateral projects and activities could fill gaps where multilateralism proves impossible. They forged ahead with their collective work to create a common glossary of terms. Finally, as they had committed to do in the 2010 action plan, they submitted national reports with a common framework. Although the reports contained only sparse instances of novel information, the exercise serves as a solid foundation for future reporting iterations. 

Between now and the 2015 review conference, two outputs of the P5 process are on the horizon: coordinated national contributions to the CTBTO field exercise in Jordan and a first version of the glossary. Beyond those, the group’s agenda looks blank.

Because of the modest rate of progress, a growing number of non-nuclear-weapon states doubt whether the promised long-term value of the P5 process will ever be realized. A majority of the nuclear-weapon states do not feel compelled to pursue new, substantially more ambitious confidence-building exercises, especially in an age of mounting Russian aggression in Europe. Yet, without an effort by the nuclear-weapon states to continue taking gradual steps and laying the foundation for future arms control agreements, the voices in the NPT community that assert that the P5 process is a hindrance or an irrelevance could grow louder. 

In this context, a robust strategy that spells out a forward-looking plan for activity by the nuclear-weapon states would demonstrate that they genuinely intend for the P5 process to continue to support NPT implementation, albeit primarily in the long term. They might therefore want to consider formulating a general post-2015 working plan that they would be able to discuss next year in New York. In doing so, it might be helpful for them to consider how the projects they have recently undertaken or can feasibly undertake in the near term could serve as stepping-stones to progressively more ambitious trust-building activities. Having such stepping-stones in place would be of particular value if relations among nuclear-weapon states improve in future. 

A Move to Minilateralism?

Admittedly, identifying new projects that all five nuclear-weapon states would find palatable is difficult. As mentioned above, although the P5 process remains active, it has not been able to isolate itself from the wider cooling of relations among the nuclear-weapon states. One project, however, seems immediately agreeable to the group: a second iteration of the glossary. 

In 2013, approximately 200 of the more than 2,000 terms submitted made the short list for definition, leaving much more work to be done. It is difficult to assess what the value of another phase of the project would be without knowing which terms made that list. If numerous terms that are relevant to arms control and disarmament did not make the first cut, for instance, revisiting them to produce common definitions could be a worthwhile exercise. Regardless, the nuclear-weapon states have implied that a second iteration of the project could appear on their post-2015 work plan. According to the joint statement from the group’s 2014 Beijing conference, the five countries are aiming to complete only the “first phase” of the glossary project by the start of the 2015 review conference.[9] 

Beyond an expanded glossary, the group could amend its common reporting framework to include some quantitative aspects of the five states’ nuclear policies. This would be highly unlikely to cover data on national nuclear arsenals, at least in the medium term, as Beijing and others remain entirely uninterested in increasing transparency in that realm. Yet, the reports submitted to the 2014 Preparatory Committee meeting indicated that commonly articulated quantitative declarations might be possible in some areas. Financial contributions to the CTBTO or other relevant international agencies or transparency visits to nuclear-weapon states by experts of those institutions, for instance, are not as sensitive. A move toward regular provision of information under these categories could encourage continued and further multilateral cooperation by nuclear-weapon states. Moreover, it could familiarize states with a process of regularized quantitative declarations that could later be expanded if security dynamics permit. 

Because some projects would not be supported by all five states, one way to make progress in increasing the number of projects that can be used to demonstrate achievement during the next review cycle would be to look for opportunities for bilateral or multilateral projects that do not have buy-in from all five nuclear-weapon states, using the P5 process to coordinate such projects. In fact, the P5 process may already be on this trajectory. Nuclear weapons laboratories in the UK and United States will most probably continue their long-standing but only recently announced program of warhead dismantlement verification research. As noted above, the UK and China are reportedly in discussions about starting their own joint research on verification. 

France, although apparently uninterested in warhead-focused work, might be open to a partnership with the UK, the United States, or both that would focus on the dismantlement of a nuclear facility. In particular, cooperation that looks at the practicalities of dismantling or disabling facilities capable of producing fissile material would have relevance for a future fissile material treaty. Since Sarkozy’s Cherbourg speech in 2008, France has sought to emphasize its decision to close nuclear facilities as a central component of its disarmament record. France boasts that it was “the first State to decide to shut down and dismantle its facilities for the production of fissile materials for explosive purposes…[and] the only State to have transparently dismantled its nuclear testing facility in the Pacific.”[10] Proposals for technical cooperation that build on France’s record in facility dismantlement, with which other nuclear-weapon states also have experience, could gain traction with a majority of these states and could catalyze a discussion that would be useful for future arms control. 

Non-nuclear-weapon states may be understandably skeptical as to whether these bilateral initiatives can properly be classified as accomplishments of a process whose main purported value is that it brings together all five recognized nuclear-weapon states. Yet, the terrain on which all members of the P5 process can find agreement is small and shrinking. In the next NPT review cycle, the most likely package of work might include only one or two multilateral projects involving all five nuclear-weapon states, but a number of other initiatives involving fewer than five. 

A shift toward this type of agenda could admittedly lead to the temptation to artificially badge activity as part of the P5 process in order to undercut any assertions that the process has stagnated. This need not be the case. Novel bilateral or minilateral[11] projects could arise that would enhance NPT implementation. For example, joint UK-Chinese activity on warhead dismantlement verification would engage traditionally reticent Beijing in cooperative, disarmament-focused work, which would undoubtedly be a step in the right direction. Participants in the P5 process could use that process to brief their fellow nuclear-weapon states on progress on these types of projects and to coordinate and expand them. To an extent, the five-country meetings already have been used in this way. For instance, they provided a forum in which Russia and the United States delivered briefings to the smaller nuclear-weapon states on New START implementation. 


The P5 process has been a useful addition to the broader system of interrelated international nuclear arrangements. It continues to provide an important mechanism through which the nuclear-weapon states are expected to demonstrate their shared commitments to fulfilling their NPT obligations. It already has yielded some modest results. More are in the pipeline for the period leading up to and including the 2015 NPT Review Conference, not least the common glossary of nuclear terms. Yet, the ability of the these five states to go beyond their current rate and depth of activity depends in large part on the improvement of broader security relations among them. 

The difficult security situation, however, does not mean that the P5 process is condemned to irrelevance until that improvement transpires. To prove this, the group should articulate a work plan for the next NPT review cycle that includes activities and accomplishments that could help facilitate future disarmament and arms control measures. New bilateral verification research partnerships, a more ambitious version of the glossary, and agreement on some common quantitative elements for national transparency declarations, for example, could be worthwhile in this respect. Undertaking and coordinating such projects in the context of the P5 process would demonstrate the value of the process as a tool that can be readily strengthened if wider strategic relations between the major nuclear powers create an opportunity for greater disarmament progress. 

When that day comes, there is likely to be strong support for an effective mechanism to coordinate and facilitate the disarmament efforts of the nuclear-weapon states. It would be better if the P5 process were at the ready, with nuclear-weapon-state officials having already worked together in a forum mindful of the NPT and the commitments that flow from it. Despite the recent deterioration of security relations among nuclear-weapon states and, as a result, in the prospects for disarmament, the P5 process is something nuclear-weapon and non-nuclear-weapon states should work to keep alive. 

Andrea Berger is a research fellow at the Royal United Services Institute in London, where Malcolm Chalmers is research director. Some of the research for this article draws on conversations conducted on a not-for-attribution basis with officials of various governments. The authors are grateful to all their interlocutors for sharing their insights.


1. The five countries that the nuclear Nonproliferation Treaty recognizes as nuclear-weapon states (China, France, Russia, the United Kingdom, and the United States) also are the five permanent members of the UN Security Council.

2. Margaret Beckett, Remarks at the Carnegie International Nonproliferation Conference, Washington, June 25, 2007,

3. France2010TNP, “Speech by Nicholas Sarkozy, President of the French Republic: Presentation of ‘Le Terrible’ Submarine in Cherbourg,” March 21, 2008, (hereinafter Sarkozy speech).

4. Office of the Press Secretary, The White House, “Remarks by President Barack Obama—Hradcany Square, Prague, Czech Republic,” April, 5, 2009,

5. See Andrea Berger and Malcolm Chalmers, “Great Expectations: The P5 Process and the Nonproliferation Treaty,” Whitehall Report, No. 3-13 (August 2013), pp. 21-26.

6. UN Web TV, “Technical Challenges in Verifying Nuclear Dismantlement,” October 25, 2013,

7. For further discussion, see Andrea Berger, “The P5 Nuclear Dialogue: Five Years On,” RUSI Occasional Paper, July 2014, annex 1. 

8. The main exception to this was the U.S. announcement of an updated total for its nuclear weapons stockpile, which fell from 5,113 in September 2009 to 4,804 in September 2013. U.S. Department of State, “Report of the United States of America Pursuant to Actions 5, 20, and 21 of the 2010 Nuclear Non-Proliferation Treaty Review Conference Final Document,” April 29, 2014, p. 7. 

9. Office of the Spokesperson, U.S. Department of State, “Joint Statement on the P5 Beijing Conference: Enhancing Strategic Confidence and Working Together to Implement the Nuclear Non-Proliferation Review Outcomes,” April 15, 2014,

10. Sarkozy speech.

11. Moisés Naím defines “minilateralism” as an approach that involves “gathering the smallest number of countries necessary to make a major change to the way the world addresses a particular issue.” Moisés Naím, “The G20 Is a Sad Sign of Our Uncooperative World,” The A-List (blog), Financial Times, February 15, 2013, In the present article, the term is used to mean an approach involving some but not all of the five nuclear-weapon states.