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Edit 12/12/2022: I made a few small changes to this post to make some attributions to other authors clearer. 

Track II (unofficial) diplomacy is potentially a useful intervention for reducing risks of great power conflict. In this post, I discuss what a paradigmatic case of track II diplomacy tells us about the value of this intervention. This case is the influence of the Pugwash Conferences on the Soviet government agreeing to place limitations on anti-ballistic missiles. 

I first motivate interest in track II diplomacy as an intervention. I then identify two important theories of change for track II diplomacy and claims about its effects which support these theories of change. I test these claims using the Pugwash case - largely discussing and scrutinising the evidence and narrative about the impact of Pugwash from political science Professor Matthew Evangelista's authoritative work on the subject, 'Unarmed Forces'. I argue that this case suggests high quality access to official decision makers, windows of opportunity for influence over policy, and the development of trusting communities of non-officials are important to the success of track II diplomacy. This case should make us more enthusiastic about using track II diplomacy to reduce risks of great power conflict. 

1. Introduction

1.1 Risks from great power conflict 

Great power conflict is an existential risk factor: the probability of an existential catastrophe grows as a major conflict becomes more likely. There are several pathways by which great power conflict raises existential risk. For example, a war between great powers could cause or accelerate the deployment of weapons with catastrophic potential, including bioweapons and nuclear weapons. Tensions or war between great powers would make it harder to coordinate on the safe development of artificial intelligence and other destabilising emerging technologies.¹

If, as seems plausible,² great power conflict significantly contributes to total existential risk, interventions to reduce the probability of such conflict could significantly decrease existential risk. 


1.2 Track II diplomacy and great power conflict

Track II diplomacy is a potentially-effective intervention to reduce risks from great power conflict. It is unofficial policy discussion, usually between parties from different sides of an international conflict or representing groups that are in tension with each other.³ Though they are not officials themselves, Track II participants can influence official actions by sharing information and policy ideas, and by advocating for their preferred approach to their contacts back home. Their non-official status distinguishes Track II diplomacy programs from Track I (official) diplomacy. Track 1.5 dialogues are unofficial discussions which include official participants.⁴

Philanthropists have funded Track II diplomacy,⁵ suggesting that, if effective, it could be a good way to use philanthropic funding to reduce risks from great power conflict. However, few formal evaluations of the effectiveness of Track II diplomacy programs exist. In this report, I present a case study of a paradigmatic example of Track II diplomacy: the influence of the Pugwash Conferences on Science and World Affairs on the Soviet government’s decision to sign the 1972 Anti-Ballistic Missile Treaty.⁶ While a case study approach raises concerns about generalisability, it can be useful when it is not feasible to conduct more systematic evaluations, such as randomised controlled trials. I use this case to test several assumptions about the effect of Track II diplomacy on relations between the countries involved. 

In the rest of this post, I first briefly discuss existing work on the effectiveness and theory of change of Track II diplomacy. I then identify key claims proponents have made about its effectiveness. I then describe the case study and discuss the extent to which it provides evidence to support these claims. I conclude that this case suggests that, at its best, track II diplomacy can have significant positive effects on relations between rival powers.  


2. Background on Track II diplomacy 

2.1 Theories of change

Proponents of Track II diplomacy generally argue that it reduces the risk of conflict by facilitating information flow and building relationships between representatives from rival countries. In a report for Founders Pledge, Stephen Clare, for example, identified several theoretical justifications for thinking that Track II diplomacy could make relations between countries safer.⁷ I consider two important models of how Track II reduces conflict risk, summarised in the diagram below (figure 1): the ‘new policy ideas’ theory of change and the ‘trust building’ theory of change. The first theory of change claims that Track II provides a setting in which new policy options can be explored by participants who understand their own party’s approach to the issues. The second claims that it provides a setting for information sharing and relationship building. I focus on these theories because they are among the most important models for why Track II programmes are effective, and are the most relevant for my case study.

Figure 1. Theories of change for Track II diplomacy

New policy ideas

Some work on Track II diplomacy claims that, particularly in cases of international tension rather than when countries are already at war, Track II dialogues can improve policy by providing a space to generate new options for engagement or for ways to reach agreements.⁸ Participants in Track II discussions understand the concerns that motivate their government’s current policy positions. In some cases, they also have detailed knowledge of the priorities of official decision makers. But, as unofficial representatives, they are also relatively free to discuss a wide range of possible policy options or new agreements. As a result, according to this view, Track II diplomacy provides an opportunity for participants to generate new policy ideas to resolve key difficulties in the relationship between the two parties. In figure 1, I have made explicit the implicit assumptions that (1) the new policy ideas are passed on to official decision makers, and that (2) official decision makers implement these new ideas. 

Trust building

Another important theory of change for Track II diplomacy focuses on the potential for opposing parties to build trust through information sharing and repeated interaction. For example, Clare argues that Track II diplomacy provides opportunities to share information about policy intentions and military capability (see fn. 8). This could make misunderstandings less likely. It could also increase each party’s confidence that the other party will uphold any agreement reached, by increasing transparency and strengthening individual relationships between negotiators. By building trust between participants and allowing them to share information, Track II diplomacy makes it more likely that parties in conflict or tension will make concessions and enter into agreements to decrease the risk of dangerous outcomes. 


2.2 Evaluating Track II diplomacy

Because it is so difficult to measure the effect of Track II interventions, most proponents rely on theories of change when advocating for their implementation. Clare’s report does identify one empirical analysis which suggests Track II diplomacy has a positive effect on the likelihood of reaching an “effective outcome” in negotiations.⁹ However, because the study is non-experimental, not supported by further analyses, and potentially lacks construct validity, he does not put much weight on this finding. Even if we were able to identify and measure outcomes with confidence, endogeneity would be a major concern. Because other factors which influence whether relations between nations improve or armed conflicts are resolved are also correlated with whether Track II diplomacy happens, it’s very hard to identify the causal effect of conducting Track II diplomacy on international tensions.

However, in a report for Founders Pledge, John Halstead has noted that impact is fat-tailed for many policy interventions (i.e., the probability of the intervention having a very large impact is higher than for a standard normal distribution). In such cases, a large proportion of the total impact of the intervention comes from a small number of big wins.¹⁰ It is plausible that the impact of Track II diplomacy programs is also fat-tailed. If this assumption is correct, then it is useful to conduct case studies to understand the counterfactual impact of the most successful Track II diplomacy programs, as the value of these successful cases largely determines the value of conducting Track II diplomacy.¹¹

The influence of the Pugwash Conferences on the Soviet government’s decision to sign the Anti-Ballistic Missile Treaty is plausibly an example of a big win for Track II diplomacy (see fn. 6). Their influence on limitations on anti-ballistic missiles is particularly important to investigate because this is a case where the Pugwash conferences potentially influenced an important outcome in US-Soviet relations. Professor of political science Matthew Evangelista, an expert on the influence of transnational networks of scientists on Soviet foreign policy, argues that Pugwash participants had a significant influence on Soviet policy in this case.¹² Agreeing to limitations on anti-ballistic missiles was also an important outcome for US-Soviet relations. 


2.3 Key claims about Track II diplomacy’s effectiveness

The ‘new policy ideas’ and ‘trust building’ theories of change make several assumptions about how Track II diplomacy improves relations between participating countries. I will scrutinise these assumptions. The claims I consider are:

Claim 1: Track II dialogues allow participants in the dialogue to come up with new solutions to policy challenges.

Claim 2: Track II dialogues change participants’ policy preferences. 

Claim 3: These changes in participants’ policy preferences would not otherwise happen.

Claim 4: Track II diplomacy can create policy change through participants relaying their ideas to governments.

Claim 5: Track II diplomacy increases each side’s confidence that the other will uphold an agreement by allowing them to share information and build relationships.

Claim 6: Track II participants improve policy outcomes by advancing mutually-acceptable solutions to challenges in the diplomatic relationship between participating countries. 


In the next two sections, I describe the case and show its relevance to these six three claims. 


3. The Pugwash Conferences and the Anti-Ballistic Missile Treaty 

3.1 Background on the Pugwash Conferences

The Pugwash Conferences convene scientists, experts, and policymakers to discuss strategies for dealing with nuclear risk and weapons of mass destruction. Participants advocate for these strategies to be implemented as policy.¹³ They began in 1957 as gatherings of elite scientists from the United States, the Soviet Union, each country’s allies, and the non-aligned countries.¹⁴ The first conference was funded by a single donor, Canadian-American businessman Cyrus Eaton, and inspired by the 1955 Russell-Einstein manifesto, which called for an end to the arms race and highlighted the dangers of nuclear war.¹⁵ Western scientists who were eager to encourage international cooperation to reduce nuclear risks played an important role.¹⁶  As well as track 1.5 and II dialogues, many other activities have been hosted under the Pugwash umbrella, including events, research projects, and study groups. The Conferences still run today.


3.2 The Anti-Ballistic Missile Treaty

Pugwash participants worked on multiple issues, but here I focus on their contribution to one arms control outcome: the Soviet Union’s decision to agree to limitations on anti-ballistic missiles, as codified in the 1972 Anti-Ballistic Missile Treaty. My source for much of the evidence  and argument for the influence of the Pugwash Conferences on anti-ballistic missile limitation is Matthew Evangelista’s ‘Unarmed Forces’.¹⁷

The Anti-Ballistic Missile Treaty limited the development and deployment of missile defence systems that use anti-ballistic missiles. Anti-ballistic missiles defend against nuclear attack by intercepting and destroying incoming nuclear missiles. The Treaty prevented both the United States and the Soviet Union from deploying a system of anti-ballistic missiles which could defend their entire territory. Each side was limited to just two systems: one around the nation’s capital, and another around an ICBM launch site. In 1974 this was further limited to one each, either around the capital or around a launch site.¹⁸ Signed as part of SALT I, the first bilateral arms control agreement between the US and the Soviet Union,¹⁹ the Treaty was in force from 1972 until the US withdrew in 2002.²⁰

The basic argument for the effect of the Pugwash Conferences in this case is:

  1. American scientists developed concerns about the destabilising effect of anti-ballistic missiles.
  2. They convinced influential Soviet scientists of these concerns at the Pugwash Conferences and other meetings with Soviet Pugwash participants.
  3. These Soviet scientists communicated these concerns to political leaders in the Soviet Union.
  4. This motivated Soviet leaders to agree to limitations on anti-ballistic missiles. 

I call the American scientists’ view the strategic stability argument against anti-ballistic missile deployment. It has two core claims:²¹

  1. Anti-ballistic missiles would worsen the nuclear arms race (be bad for ‘arms race stability’). Suppose the opposing country deploys a comprehensive system of anti-ballistic missiles. The simplest and cheapest way to respond to this would be to increase the number of your nuclear warheads until your arsenal is big enough that it can overwhelm the other side’s new defences. 
  2. Anti-ballistic missiles make it more likely that moments of crisis will escalate to nuclear war (be bad for ‘crisis stability’). If both sides have them, the side which strikes first will have an advantage in a nuclear war - their defences will only have to respond to a comparatively ragged and weak second strike. So, in cases where each side fears the other might attack, there is an incentive to strike first.

In the next section, I assess the extent to which this case provides support for the six key claims about Track II diplomacy. This article by Paul Rubinson also gives an overview of key claims in the literature about the influence of Pugwash on policy, including in the case of anti-ballistic missiles.


4. Support for claims about the effect of Track II diplomacy

4.1. Claim 1: Generating new policy ideas

Some proponents suggest that Track II diplomacy can provide space for dialogue that generates new policy ideas. While this claim may be true, this case does not provide any positive evidence to support it. American scientists independently became concerned about the destabilising potential of anti-ballistic missiles.²² Instead of working to develop new policy ideas, the Americans made concerted efforts to convince Soviet scientists of their own perspective.²³


4.2. Claim 2: Changing participants’ policy preferences

Claim 2 suggests that Track II dialogues can have an impact by changing participants’ policy preferences or strategies for advocating for their preferred policies. 

The Pugwash case provides some strong evidence in support of this claim. It is highly likely that American scientists successfully persuaded some Soviet scientists to change their minds about missile defence. There is specific evidence that this happened in the case of at least one important scientist, mostly identified by Evangelista. Sources on the views of the head of the Soviet Pugwash delegation vary, but suggest that he was deeply sceptical of American scientists’ arguments against anti-ballistic missiles in January 1964,²⁴ and more sympathetic to them by later that year after participating in additional, informal meetings with American scientists. Two American scientists who met him before and after his change of mind suggest that these meetings in the interim made him sympathetic to the American position.²⁵ Since little has been recorded about Soviet scientists’ views, specific evidence that the head of the Soviet Pugwash delegation was convinced by American scientists suggests that others likely were as well. 

The Pugwash conferences were not the only opportunity for American and Soviet scientists to discuss arms control and US-Soviet relations. Informal meetings and confidential bilateral Track II dialogues complemented the Pugwash conferences.²⁶ In fact, Evangelista's evidence suggests that being able to meet outside of the main conferences was crucially important for providing enough contact to convince Soviet scientists of a new perspective on this arms control question.²⁷

However, these additional meetings were only possible because the Pugwash Conferences helped to create strong connections between American and Soviet scientists.²⁸ When the first Pugwash conference happened in 1957, there were either no, or almost no, other opportunities for Soviet and American scientists to have conversations about security policy and nuclear issues,²⁹ and personal networks between the scientists did not yet exist.³⁰ The Pugwash conferences therefore opened the door to extensive contact which was crucially important for American scientists who wanted to persuade their Soviet peers of their perspective on the anti-ballistic missile issue. 

There are reasons to think that there was initial scepticism about the strategic stability argument among Soviet scientists. Evangelista's evidence indicates this was the case for at least two important Pugwash attendees.³¹ Additionally, the broader perspective on nuclear strategy which motivated American scientists’ concerns would have been novel for many of the Soviet Pugwash delegation. One part of the argument against anti-ballistic missiles is that they provide an incentive to strike first, but at this time the Soviet military was still focussed on having the capability to preempt an American attack and strike first in a moment of crisis.³² This does not show that Soviet scientists were convinced of the perspective of Soviet nuclear strategists, but it does suggest that the perspective which motivated the argument would have been unfamiliar.

The case of Pugwash therefore supports the view that extensive contact between non-officials from parties to an international conflict can change these non-officials’ policy preferences. It also provides support for thinking that this kind of contact can be established even when relations between two countries are very strained and existing opportunities for contact between non-officials are extremely poor - over time, Track II diplomacy can build networks of cooperating policy advocates. 


4.3. Claim 3: The changes in policy preferences are counterfactual

If Track II dialogues merely replace other forms of communication which would produce the same changes in policy preferences, they are not useful. However, there are a few obvious reasons to think that, in the case of Pugwash, Track II dialogues and attendant discussions did provide a uniquely good venue for changing Soviet scientists’ minds. 

First, American scientists had unique opportunities to discuss strategic concerns about anti-ballistic missiles from a Soviet perspective, and from the perspective of mutual strategic interests. At the time, the other way Soviet scientists could have accessed the strategic critique of anti-ballistic missiles was through American writings in journals and periodicals and by following Soviet analyses of American political debates³³ - these would have discussed concerns about anti-ballistic missiles from the perspective of American strategic interests, and so would have been less persuasive.

Second, the Conferences led to comparatively trusting relationships between Soviet and American scientists.³⁴ As a result, Soviet Pugwash participants would have been more confident that these Americans sincerely believed that it was in the Soviet interest to limit anti-ballistic missiles than if they were uncertain of the intentions and loyalties of the American delegation. They would certainly have been more confident in the scientists’ sincerity than Soviet leaders would have been in the sincerity of American officials who favoured limitations on the technology. 

Finally, because of opportunities for extensive in-person dialogue between Soviet and American scientists, American scientists had multiple opportunities to try to persuade their Soviet contacts of this perspective, if they were initially sceptical or unconvinced by the first presentations of the argument.

There is some evidence that opposition to anti-ballistic missile development was growing among Soviet citizens independently of their meetings with American scientists. Evangelista argues that some Soviet citizens opposed anti-ballistic missiles because of a combination of their own reflections on the technology and reading American arguments - including scientists and non-scientists who never attended Pugwash.³⁵ This suggests that Pugwash participants and Soviet leaders may have eventually supported limitations on anti-ballistic missiles even absent the influence of Pugwash. However, he also suggests that those Soviet scientists who were persuaded of the American view outside of Pugwash had unusually independent and critical perspectives on Soviet policy (see fn. 35). 

Overall, it seems likely to me that the influence of the Pugwash Conferences on Soviet scientists’ views was counterfactual. They provided opportunities to discuss security policy at a time when the only other way to engage with Americans on these questions was by reading about their arguments from afar. Thus, the case of Pugwash supports the idea that, when existing opportunities for communication between key non-officials in different countries are poor, Track II diplomacy can be a highly-valuable forum for knowledge exchange and deliberation on important policy questions. 


4.4. Claim 4: Relaying policy ideas to governments

Track II dialogues can only have significant effects if participants affect policy makers' decisions. Therefore, it is important to examine the claim that Soviet Pugwash scientists made a difference to their government’s perspective on anti-ballistic missiles, and if so, how. 


The advocacy of Soviet scientists

Soviet scientists who took part in Pugwash had opportunities to communicate their opposition to anti-ballistic missiles to top political leaders, including the Soviet leader Brezhnev, the Prime Minister, and members of the Commission on Arms Control. As Evangelista argues,³⁶ the most significant way scientists could have affected the Soviet stance on anti-ballistic missile limitation is by influencing the attitudes of this small group of political leaders. This group made the decisions that took the Soviet Union from being approached by the US about potential arms control talks to signing the Anti-Ballistic Missile Treaty.³⁷

Evangelista attempts to show that scientists had an influence on the Soviet government’s stance via this route by providing evidence that they had opportunities to communicate their views to leaders and that they took these opportunities at key moments. Scientists who attended Pugwash had personal and institutional connections to leaders and members of the Commission on Arms Control. Some of their scientific higher-ups with whom they would have discussed arms control and conversations at Pugwash were also close with and greatly respected by the top political leadership.³⁸ Unfortunately, there is only very limited evidence that scientists appealed directly to leaders.³⁹ There is very limited evidence in general about what advice Soviet leaders received on arms control, due to the secrecy surrounding Soviet policy making and the amount of time that has passed. So a lack of evidence of direct communication between scientists and policymakers should not be taken as a strong indication that no such talks occurred. 

In public communications, and in private communications with the Americans, the Soviet government endorsed a strategic rationale for limiting anti-ballistic missiles.⁴⁰ As Evangelista argues, this provides further evidence that actors who were concerned about strategic stability had familiarised Soviet political leaders with their arguments. However, I do not think this provides strong evidence that Soviet leaders believed the strategic stability argument against anti-ballistic missiles: it is possible that Soviet leaders talked in terms of the Americans’ strategic concerns to make it easier to communicate their willingness to negotiate.⁴¹


Scientists plausibly made a difference

Even assuming that scientists conveyed their opposition to anti-ballistic missiles directly to key political decision makers in the Soviet Union, this does not show that their advocacy was necessary to get political leaders to agree to place limits on the technology. 

Suppose scientists had not communicated concerns about the strategic implications of anti-ballistic missiles to the political leadership. In that case, political leaders would still have accessed the strategic argument against anti-ballistic missiles from American officials who were sympathetic to it. It is likely that listening to American officials express such concerns about anti-ballistic missiles, before and during the SALT talks, contributed to Soviet leaders’ support for limiting them.⁴²

Beyond worrying that the further development and deployment of anti-ballistic missiles would be destabilising, political leaders in the Soviet Union had other reasons to want to limit this technology. Evangelista argues none of these other considerations gave leaders decisive justifications to support anti-ballistic missile limitation.⁴³ But is he right about that? According to both Kaufman⁴⁴ and Evangelista,⁴⁵ in the lead up to the bilateral agreement to limit anti-ballistic missiles, the desire to achieve any arms control win was a significant driving force behind Brezhnev and the Prime Minister’s willingness to accept these limitations. That said, it seems unlikely to me that their desire for an arms control agreement to improve relations with the US would have been sufficient to make the Soviet government agree to limit anti-ballistic missiles. If they did not believe in the strategic rationale for limiting the technology, and were optimistic about developing new anti-ballistic missile systems, it is implausible that they would have been willing to give up opportunities to deploy more. 

However, it is plausible that by the time they were making decisions about the Soviet negotiating position in the SALT talks, political leaders were convinced that it would be infeasible to create an anti-ballistic missile system which had any strategic relevance. The available evidence makes it unclear whether or not they still had some optimism about this technology.⁴⁶ If they had become convinced that effective defence was infeasible, then agreeing to limit the deployment of anti-ballistic missiles would have had next to no consequences for Soviet strategy or military plans. On this account, limiting missile defences was an arms control option which the Soviet leadership could pursue with little cost. Political leaders could simply have been eager to reach an agreement and convinced that anti-ballistic missiles would not be useful anyway.⁴⁷

I think two possibilities are about equally likely. The first is that technical advisors to the political leadership were all pessimistic about anti-ballistic missile technology, and leaders decided to support extensive bilateral limitations on anti-ballistic missiles because this would be a major arms control win and have little effect on military strategy or plans for new weapons developments. In that case, political leaders would have agreed to limit anti-ballistic missiles regardless of whether they were convinced that the technology could be destabilising. The second (which is Evangelista's view⁴⁸) is that there was still significant misguided optimism about the technical prospects for anti-ballistic missiles. I think that accepting this second possibility should also lead us to accept Evangelista’s broader view that, other than concerns about strategic stability as raised by scientists, there are no considerations that decisively favoured Soviet leaders supporting limitations on anti-ballistic missiles. Other proposed explanations for the Soviet government’s decision, which I do not discuss in this post, are weak. So the second view suggests that hearing scientists’ concerns would have been crucially important for swaying political leaders to agree to anti-ballistic missile limitations. 

Since there is a good case that Pugwash participants had a counterfactual influence on the policy outcome, I think it is right to treat the effect of Pugwash on the Anti-Ballistic Missile Treaty as an example of a big win for Track II diplomacy. This study supports the idea that Track II diplomacy initiatives have a high upside, though not as much as if the available evidence allowed us to be more confident that Pugwash participants had an influence on the policy outcome. 

The case of Pugwash suggests that Track II practitioners can make a difference to policy especially when there is a key window of opportunity to do so: an opportunity for policy change arises, and other considerations mean that political leaders are already interested in Track II practitioners’ preferred policy.


Scientists’ narrow influence 

Some evidence suggests that Pugwash scientists influenced the Soviet leadership to favour a perspective on nuclear strategy which can motivate wanting to limit missile defences. Political scientist David Holloway identifies a shift in Soviet nuclear strategy over the course of the 1960s, from a focus on being able to preemptively attack a rival power in a situation where it is planning to launch a first strike, to a focus on deterring the rival from attack by ensuring the ability to launch a devastating second strike is preserved.⁴⁹ The strategic stability argument against anti-ballistic missiles is more compelling if you already accept that nuclear forces should be set up to preserve deterrence capability. In particular, worrying about ‘crisis stability’ makes little sense if you plan to preemptively strike the other side in a moment of crisis. 

The shift in nuclear strategy - to the extent that it affected the views of the top leadership - would have made those leaders more receptive to the idea of limiting anti-ballistic missiles. Pugwash scientists may have contributed to this broader shift in strategy by relaying American ideas about nuclear deterrence to political leaders. We know of one instance where the President of the Soviet Academy of Sciences (who would have discussed arms control with Pugwash scientists), argued in favour of focussing on deterrence at a key meeting about offensive forces.⁵⁰

However, it is a lot less likely that Pugwash scientists decisively influenced this broader shift in Soviet strategy than that they tipped the balance on the anti-ballistic missile question in particular. This is because the shift in Soviet strategy was a much broader change, because there are multiple potential explanations for it, and because much of the impetus for this shift came from the military rather than the political leadership.⁵¹


Beyond direct communication to the leaders

As well as scientists directly sharing their views on anti-ballistic missiles with political leaders, the Soviet government’s interest in closely following discussions at Pugwash likely exposed them to the strategic ideas that were discussed at the Conferences. This is one set of evidence Evangelista draws on to support the impact of scientists on political leaders’ views on missile defence (the others are discussed in the first subsection of 4.4 and the notes to that subsection). Particularly in the early years of the Conferences, the Soviet government hoped that Pugwash would be a tool for spreading propaganda and promoting their own foreign policy agenda. They therefore tried, with mixed success, to closely track and dictate the activities of the Soviet delegation at the conferences.⁵²

By the time Pugwash participants became interested in the anti-ballistic missile issue, the Soviet government’s control over the activities of their Pugwash delegation had weakened.⁵³ Nevertheless, they did monitor their activities at this time. Evangelista records some specific examples of the Soviet government taking interest in Pugwash discussions of the anti-ballistic missile issue. Disagreement within the Soviet Pugwash delegation at a 1967 conference (a leading scientist argued in favour of limiting anti-ballistic missiles, whilst a military official opposed limiting them) caught the attention of political leaders.⁵⁴ Officials from the Soviet government attended a meeting of the Soviet-American Disarmament Study Group (one of the forums for bilateral US-Soviet track II dialogue which began as a result of Pugwash) in December 1967.⁵⁵ Evangelista also argues that a Soviet Pugwash attendee who was a KGB agent could have reported on the meetings directly to the top political leadership.⁵⁶

Overall, this section shows that, while there are multiple ways that Soviet Pugwash participants may have influenced Soviet policy makers, it is difficult to prove they had an influence. Nevertheless, I accept Evangelista's case that because (1) the Pugwash Conferences were well-known, (2) the participants were prestigious and connected to Soviet leaders, and (3) Soviet leaders came to understand the strategic concern about anti-ballistic missiles in the period when Soviet scientists were advocating for this concern, it is likely that the participants influenced policy makers’ attitudes to anti-ballistic missiles. It is similarly difficult to determine whether Pugwash participants’ influence on policy makers’ attitudes was necessary to get them to agree to limitations: it is hard to know how strongly concerns about the feasibility of the technology and the desire to achieve a win on arms control influenced policy makers’ decision. However, there is a plausible case that these considerations were not enough on their own, and that therefore, influence from scientists was necessary for them to agree to anti-ballistic missile limitations. 


4.5. Claim 5: Information sharing and relationship building

Sharing information, for example about policy intentions and military capability, can make it easier to reach agreements on arms control. Information sharing decreases the risk of misunderstanding and miscalculation. However, in the case of the agreement on limitations to anti-ballistic missiles, the Pugwash Conferences were not an important route for the US and Soviet governments to share information about their intentions and current capabilities. There is no available evidence of the US and Soviet governments using the Pugwash Conferences as a channel to share information about their plans for anti-ballistic missile development or the considerations affecting whether and what limitations on anti-ballistic missiles they would agree to. It would be surprising if they did, as the Pugwash conferences were not closely connected to the official negotiations where the details of anti-ballistic missile capabilities and potential options for limiting them were discussed. This is in contrast to some Track II dialogues which are focussed on helping facilitate the negotiation of specific agreements, and which happen in parallel to and in connection with official negotiations. 

Nevertheless, another claim of this theory of change for Track II diplomacy is that participants can use Track II dialogues to build relationships, creating trust in each others’ intentions. I think that the Pugwash conferences provided a venue for this type of trust building and networking between scientists on either side of the Cold War divide. But this probably did not translate into increased trust between officials in the US and Soviet Union. And it did not make it easier to reach agreements by increasing confidence that the other country would uphold them, instead it did so by facilitating discussions about the policy implications of their shared aims of peaceful relations and arms control.  

In light of the pressures on the Soviet Pugwash delegation, it is particularly impressive that they were able to build trusting relationships with Western scientists by establishing a shared set of aims. Lüscher, focussing on Pugwash pre-1960, discusses how the Soviet government wanted the conferences to be a tool to spread their existing foreign policy agenda, and used both their control over which scientists could attend and surveillance to constrain what positions Soviet participants supported (see fn. 52). He argues that the Soviet delegation carefully balanced the risks of losing their position at the conferences by too loudly adopting stances which contradicted those of their government, and of failing to cooperate effectively with Western scientists by not demonstrating that they shared their aims and were in fact interested in compromises between Soviet and Western interests.⁵⁷ This balancing act was particularly important as it was reasonable for Western scientists to be concerned about the aims and loyalties of their Soviet peers: at the time, the Soviet government was supporting other international conferences on peace and disarmament with the aim of spreading the Soviet foreign policy agenda.⁵⁸


4.6. Claim 6: Developing mutually-acceptable solutions

Track II diplomacy is worth supporting because it is a potential mechanism for improving policy, not merely changing it. Here, I look at whether and how the policy change in the Pugwash case had positive effects: did the Treaty decrease the risk of US-Soviet conflict? And was limiting anti-ballistic missiles a good focus for proponents of arms control, given what was known at the time?  

The signing of the Anti-Ballistic Missile Treaty improved US-Soviet relations. The SALT I agreement, which included the Treaty and an agreement on offensive arms, was the first bilateral arms control agreement between the USA and the USSR. It is widely claimed that this agreement laid the groundwork for future arms control talks between the Soviet Union and the United States,⁵⁹ that it made US-Soviet diplomacy easier, and that it contributed to the improvement in US-Soviet relations in the 1970s.⁶⁰ Even if the arms controls which are codified in the Anti-Ballistic Missile Treaty did nothing to directly reduce the risks of and from a nuclear conflict, the Treaty was still very useful.

There is one particularly interesting way in which the SALT I agreement and the Anti-Ballistic Missile Treaty improved US-Soviet relations and made it easier to negotiate future arms control agreements. The agreement represented and signalled significant alignment between the United States and the Soviet Union about nuclear strategy. In particular, both sides at least outwardly accepted that missile defences could be destabilising, that parity in the size of their nuclear forces was desirable, and that the logic of deterrence made sense.⁶¹ It is possible that the Soviet Union communicated in terms of Americans’ strategic concerns to demonstrate their willingness to negotiate. Regardless, alignment in the two nations’ stated aims for nuclear strategy (whether genuine or feigned) would have decreased each country’s uncertainty about the other’s intentions for their nuclear forces. This would have directly decreased hostility between the US and Soviet Union,⁶² and also made it easier to negotiate future arms control agreements because each side was more confident in the other’s aims for their nuclear forces.⁶³

Therefore, it was valuable for the SALT I agreement to signal alignment between the US and Soviet Union on nuclear strategy. And Pugwash scientists very likely helped Soviet leaders understand the perspective on missile defence which originated in America and eventually guided the Americans’ own approach to anti-ballistic missile limitation. More speculatively, they might also have influenced Soviet leaders’ thinking about nuclear strategy more broadly. To the extent that Pugwash contributed to the alignment between the US and the Soviet Union on ideas about nuclear strategy, it was very beneficial. 

However, I think that in practice, limiting anti-ballistic missiles only had a small direct effect on the arms race and the risk of US-Soviet nuclear war. First, because I find it implausible that the buildup of deployable nuclear warheads would have been significantly worse after 1972 if anti-ballistic missile development had been allowed to continue unabated. Though the US stockpile of nuclear warheads grew and then declined slightly after 1972, the Soviet stockpile continued to grow at pace.⁶⁴ Since the buildup of nuclear arms on the Soviet side was rapid in this period, I find it implausible that it would have been much faster in a counterfactual where new anti-ballistic missile systems were allowed.

Second, I think that by 1972, the Soviet government was relatively pessimistic about the near-term prospects for anti-ballistic missile development, largely because of the failure of existing projects and internal assessments that the technology was unviable. Though there was division in the US about the prospects for limited anti-ballistic missile systems, there were no plans to build a system to defend against a full scale Soviet attack. As a result, the Treaty had few consequences for near term plans to develop and deploy anti-ballistic missile systems in either country.⁶⁵ So the Treaty did little to prevent a major proliferation of anti-ballistic missiles in the immediate years after 1972 - this proliferation would not have happened anyway. 

Finally, I think it is unlikely that the Anti-Ballistic Missile Treaty prevented deployment of missile defences that would have threatened strategic stability even in the longer term.⁶⁶

Nevertheless, given the information scientists had at the time, limiting anti-ballistic missiles was a good idea. When American scientists began to advocate against the technology, there were already reasons to suspect it would be very hard to build an effective system.⁶⁷ However, the Soviet Union and the United States were both pursuing anti-ballistic missile development.⁶⁸ It was therefore reasonable to predict that one country might produce an effective system, or at least a system that seemed effective enough for the other to fear that its offensive capability was threatened. Given that prediction, the strategic stability argument provides good reason for favouring limitations on anti-ballistic missiles. 

Although the strategic stability argument was not developed at Pugwash, the Conferences provided a venue for very early adoption and discussion of it. Given what scientists knew about the potential for anti-ballistic missile technology at the time, this argument highlighted an important opportunity for curbing the arms race and preventing future crises from escalating into nuclear war. Additionally, whether they were aware of this or not, scientists ended up advocating against a technology on which leaders were unusually disposed to place severe constraints - because they were pessimistic about whether it would be useful. Pugwash was therefore a mechanism for the adoption of a good proposal for reducing nuclear risk. 


5. Discussion 

5.1 Sources of success for Track II diplomacy 

Overall, the basic case for the importance of the Pugwash Conferences holds. Although it is hard to establish with  high-confidence the various reasons for policy shifts and decisions in the Soviet Union in the early 1970s, it seems likely that the Pugwash Conferences (1) provided a venue for bilateral discussion of policy options and potential international agreements, (2) built trust between participants, (3) led to changes in the policy preferences of Soviet participants, and (4) motivated Soviet scientists to advocate for the adoption of limitations on anti-ballistic missiles to high-level decision-makers. That makes the Pugwash case a relatively compelling example of how Track II diplomacy can have a positive effect and reduce risks from great power conflict.

A summary of my findings with respect to the six key claims is:

ClaimEvidence from Pugwash
1. New policy ideasNo positive evidence
2. Changing policy preferencesStrong positive evidence
3. Counterfactual changes in preferencesWeak positive evidence
4. Relaying ideas to governmentsWeak positive evidence
5. Information sharing and relationship buildingNo positive evidence for information sharing; strong positive evidence for relationship building
6. Mutually-acceptable solutionsWeak positive evidence

Connections to official decision makers

This study provides support for thinking that, in the best case, Track II diplomacy programs can have very significant effects in situations where participants in the dialogue have access to official decision makers. Pugwash scientists chiefly influenced the policy outcome via their high quality connections in government. This makes it plausible that, in cases where participants in Track II dialogue lack direct government connections, the potential influence of Track II diplomacy on government policy is much less significant. That said, finding other cases where practitioners did not have direct, high quality access to the political leadership but still made a difference could suggest this tentative conclusion is wrong.  

Windows of opportunity for changing government policy 

If Pugwash participants ultimately influenced the policy outcome in the case of anti-ballistic missiles, it was because there was a window of opportunity for influence. The advocacy of respected scientists gave leaders additional reason to support a policy which they would already have been strongly disposed to favour because of other considerations. As a result, Pugwash participants were able to push the Soviet government towards a policy which was consistent with reducing the risks from anti-ballistic missiles they were most concerned about. They did this without convincing them of the strategic paradigm which most supported implementing that policy. 

This case suggests that Track II dialogues could increase the probability that already-proposed arms control agreements are accepted by great powers. However, this case does little to support the view that Track II diplomacy can improve great power relations by broadly changing leaders’ attitudes to rival powers or generating innovative policies (it does not suggest that Track II dialogues cannot achieve these outcomes – it just does not provide any evidence for or against this claim).

Communities of influential non-officials 

The Pugwash conferences began at a time when there were very limited opportunities for Soviet and American scientists to meet, and facilitated the development of a transnational community of scientists advocating to reduce international tension and nuclear risk. Personal connections between scientists, frequent contact, and trust in each others’ intentions were crucially valuable when American scientists were trying to convince their Soviet peers of their perspective on the risks from anti-ballistic missile development. Soviet and American scientists were able to build trusting relationships because the Soviets astutely balanced the requirement to further the foreign policy aims of the Communist Party with their commitment to the goals they shared with Western scientists. 

This case therefore makes me suspect that Track II dialogues where contact between participants is infrequent, where there is a lack of trust between participants, and where there are no mechanisms to build personal connections and trust over time, are less promising. This case also highlights how building trusting relationships between Track II participants can be difficult when a government seeks to use a Track II dialogue to further their existing foreign policy agenda. As a result, some participants not being able to speak freely and develop mutual aims with those from other countries due to government interference is potentially a key barrier to the success of Track II. 


5.2 Limitations 

There are several potential routes to impact for Track II diplomacy about which this case reveals nothing because they don’t apply to the influence of Pugwash on the Anti-Ballistic Missile Treaty. Some key examples are: the use of Track II diplomacy to avoid misunderstandings escalating into war (see fn. 8); using Track II diplomacy as a low cost way to start negotiations with a hostile power, then gradually involving official negotiators⁶⁹ and influencing the decisions of the government through changing public attitudes on a particular policy question.⁷⁰

The case study approach also raises concerns about generalisability. In particular, Pugwash is disanalogous with some other examples of Track II diplomacy because participants on the Soviet side had such high quality connections to the political leadership. The fact that Pugwash participants were able to influence an important arms control question tells us little about the potential best-case impact of Track II programs where practitioners have significantly worse access to key decision makers.

My main resource for the argument that Pugwash had significant influence on anti-ballistic missile limitation, and the routes by which it had that influence, was Matthew Evangelista’s work ‘Unarmed Forces’. Though I think there are plausible justifications for focussing on the routes by which Pugwash had influence which I have assessed in this report, one reason why I focus on them is arbitrary: they are the routes to impact which have already been discussed and substantiated in the very narrow literature on Pugwash, in particular, Evangelista’s work.

I have not discussed potential risks from Track II diplomacy or what the case of Pugwash and anti-ballistic missiles reveals about them. It is important to understand the ways in which Track II diplomacy could make policy worse or otherwise increase tensions between great powers. If these risks are few, easy to mitigate, and the worst case outcome is not very bad, then the potential benefit from Track II programs must be much lower for the risks to be worth it, than if they are extensive and very bad in the worst case. As a starting point for thinking about downsides of Track II diplomacy, see Clare’s report.⁷¹


6. Conclusion

The Pugwash conferences affected the Soviet government’s attitude to anti-ballistic missile limitation, and plausibly made them support limitations on the technology when they would not have done otherwise. This is a proof of concept indicating that Track II diplomacy can have very large effects on policies that are important for great power relations. 

This case largely supports the ‘new policy ideas’ theory of change for Track II diplomacy, except that it is an example of an idea for policy improvement being transferred rather than created during Track II dialogue. The case of Pugwash does not provide positive support for the idea that track II dialogues can make agreements more likely through information sharing. However, it does provide support for thinking that Track II dialogues can be important for building trust between participants so they can cooperate more effectively. 

Powerful connections in the Soviet government, trust and frequent contact between American and Soviet scientists, and a window of opportunity where the government was already interested in supporting a particular arms control proposal were key to the success of Pugwash in this case. These three factors are therefore potentially important to the success of Track II diplomacy more generally.

Overall, this case should make philanthropists interested in reducing risks of great power conflict more optimistic about supporting track II diplomacy.


Footnotes and bibliography 

See this document. 


Thanks to Christian Ruhl, John Halstead, and Matthijs Maas for feedback on this report, and to Stephen Clare for both feedback and excellent research mentorship. I am grateful to the Forethought Foundation for supporting this work. 

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Congrats on this report Rani - it's excellent, and an important contribution to the longtermist conflict research literature.

The post is long and detailed, so I want to draw out the big implications for Forum readers who are less immersed in what's going on with this kind of research. The story you tell in this report is something like:

  • Track II diplomacy is particularly interesting among interventions to reduce conflict risks because it's more direct than research and can easily be funded by philanthropists
  • But it's really hard to evaluate the effect of Track II dialogues because they don't happen that often, we can't do RCT or RCT-like studies, and many factors influence both the feasibility of Track II and the outcomes of conflict (endogeneity)
  • We have some hope, though, because as John Halstead points out in "Evaluating Policy Organisations", for policy interventions we just need to know how big the biggest wins were - that's where (almost) all the impact comes from
  • So we can just look at a few cases, and do the messy, journalistic work of reconstructing the theory (and practice) of change to understand what actually happened, and whether the dialogues had an effect
  • Because we're looking for big wins, you do this for the Pugwash Conferences, the paradigmatic example of Track II dialogues

Before you started this project, I was genuinely unsure about what you'd find . The Pugwash Conferences are so narratively compelling (inspired by Einstein-Russell, involving scientists from around the world, etc.) that it was plausible to me that they became famous for being cool, not for having a policy impact. But your conclusion is that it seems pretty likely that they did have an effect! That the dialogues allowed the Americans and Soviets to build relationships and exchange arguments, and that this led some participants to change their mind on important issues. The Soviet scientists then went on to influence policymakers.

Of course, it's hard to be certain. John discusses the problems with reconstructing these case studies for contemporary policy organisations. It's even harder when you're reconstructing a case that happened 50 years ago and involved policy changes within a secretive government that worked in a language you don't speak! But in section 4 you get really stuck into the details and make a relatively compelling case for thinking the dialogues made a difference.

I'm really impressed with your work on this post! I've updated towards thinking Track II dialogues will be worth funding in certain cases, and we should definitely be looking for Pugwash-like opportunities to support (there are clear parallels between the Anti-Ballistic Missile Treaty and various military AI or other emerging tech issues today).

(Disclaimer: I supervised Rani this summer while she wrote this report)

Hi Rani, it’s great to see the report out. It’s good to have this clear deep dive on the canonical case. I especially like that it points to some attributes of track II dialogues that we should pay special attention to when evaluating them as potential interventions. Great work!

This is really great work! Very clearly structured and written, persuasively argued and (fairly) well supported by the evidence.

I’m currently doing my PhD/DPhil on the history of arms control agreements, and 1972 is one of my four case-studies. So obviously I think its really important and interesting, and that more people should know about it – and I have a lot of views on the subject! So I’ve got a few thoughts on methodology, further literature and possible extensions which I’ll share below. But they’re all to adding to what is excellent work.


Its a bit unclear to me what your claim is for the link between these Track II discussions and the ultimate outcome of the two 1972 agreements. Its not that they were sufficient (needed SALT negotiations, and even then needed Kissinger/Dobrynin backchannel). Is it that the discussions were necessary for the outcome? Or just that they contributed in a positive way? I would be interested in your view.

The limitations section is good. But I think you could have been even clearer on the limits and strengths of a ‘single N’ approach. The limits are how much this can be generalised to the entire ‘universe of cases’. However, single N also has strengths - its most useful for developing and exploring mechanisms. So I think you could frame your contribution as exploring and deepening an analysis of the mechanisms. For example, something like "Two main mechanisms are proposed in the literature, this case study provides strong evidence for mechanism 1 (conveying new conceptions/ideas) and demonstrates how it works".

On another point, I'd be concerned that if you chose this case because it was one of the most successful Track II cases you'd be ‘selecting on the dependent variable’ (apologies for the political science jargon – something like “cherrypicked for having a particular outcome”) . Can you justify your motivation and case-selection differently, for example as one of (the?) biggest and most sustained Track 2 dialogues? e.g. you say: “when the first Pugwash conference happened in 1957, there were either no, or almost no, other opportunities for Soviet and American scientists to have conversations about security policy and nuclear issues”

Further literature

Adler + Schelling are great on the US side of the story. I assume you would be familiar with them, but I don’t see them cited. If you haven’t read them, you’re in for a treat – they’re great, and largely agree with you.

If you want to go down a tangent, you might want to engage with new line of argument that many US nuclear policymakers never accepted the parity of MAD, but continued seeking advantage (Green and Long 2017;  Green 2020; Lieber and Press 2006, 2020; Long and Green 2015).

As a sidenote, I’m curious why so much of the research on the two nuclear 1972 agreements focusses on ABM. ABM is the more intellectually interesting and counterintuitive. But its not clear to me it was *more important* then the limits on offensive weapons though.

Next steps/possible extensions

My impression is your main audiences are funders (and to a lesser extent general researchers and activists) within GCR. However if you wanted to adapt it, this very plausibly could be a paper. Its already a paper length, ~8,000 words. If you wanted to go down that route, there's a few things I'd do:

  • I’d cut most of the personal best guesses (“it seems likely to me” etc).  
  • I think the notes are really great and interesting! If you incorporated some of them in the text of the piece you could deepen some of your claims in section 4, slim down the other sections.
  • Have a paragraph or two placing this piece within wider IR theoretical debates on constructivism, epistemic communities, going against systemic theories to open the 'black box' of the unitary state, etc.

If you wanted to continue this research, you could contrast this case with a similar conference and see what the difference in outcomes was; or try and draw up a list of the whole universe of cases (all major Track II dialogues).

Thanks for this comment, and for the suggestions of literature and potential next directions! I'm excited to hear that arms control agreements are your main research focus and would like to hear about what you've found. 

My claim about the link between these track II discussions and the ultimate outcome of the negotiations is that (if they had any effect!) they contributed in a positive way because they were necessary for the Soviet negotiators to propose extensive limitations on anti-ballistic missiles and for the Soviet side to be enthusiastic about reaching some kind of extensive agreement on ABM. I don't think Pugwash discussions were necessary for the ultimate outcome of the ABM Treaty. That's because I think there's some chance that if the Soviets had not proposed extensive limits on ABM, the specifics of bargaining during the negotiations would have made them want to accept an American proposal for such limitations, even if other considerations left them enthusiastic about developing missile defences . My guess is that those scenarios are quite unlikely, so that Pugwash made a very signfiicant positive contribution to achieving an agreement on ABM. That said, I did not spend very much research time looking at the details of the SALT negotiations. I think Pugwash probably had only a very limited influence, if any, on the agreement on offensive systems (also, I think you're right that the agreement on offensive systems is underemphasised and probably had more important effects on the arms race - as I discuss briefly in 4.6, I think ABM turned out to be a bit of a side issue in slowing the progress of the arms race).

I really like your idea of emphasising that n=1 case studies can reveal mechanisms, and I agree that's an important strength of this kind of study.This is the most important original contribution of this research - as I mentioned in the report, the argument for the influence of Pugwash has largely already been made by Matthew Evangelista, and I'm mostly trying to figure out what it means for the mechanisms of impact for track II. 

When it comes to the 'selecting on the dependent variable' concern - I feel like this would be more of a worry if my study was trying to say something about the likely impact of a typical track II dialogue. However, I see this study as instead trying to say something about how high the high upside of track II can be, which matters a lot if the impact of these kinds of programs is fat tailed (as I briefly discuss in 2.2). That said, understanding the impact of more typical cases of track II is also important for figuring out how rare big wins are and whether these programs consistently have modest positive effects or just usually fail to do anything. And Pugwash certainly is one of the most major and sustained track II dialogues between countries not in active armed conflict and focussed on arms control - so it is a natural one to look at if you're focussing on track II for improving great power relations. 

Thanks again for the feedback and suggestions!

Thanks very much for this write-up, I learned a lot from it!

I’m a bit confused by your position on the counterfactual impact of Pugwash on political leaders’ views.

On the one hand:

  • You say in your summary table that there is ‘weak positive evidence’ for Claim 4, the full version of which is that “Soviet Pugwash scientists made a difference to their government’s perspective on anti-ballistic missiles." (as an aside, I think it would be clearer to change the shorthand for Claim 4 from 'Relaying ideas to governments' to something that highlights the necessity for counterfactual change, e.g. 'Counterfactually changing government position')
  • You write in the section on Claim 4, “Since there is a good case that Pugwash participants had a counterfactual influence on the policy outcome, I think it is right to treat the effect of Pugwash on the Anti-Ballistic Missile Treaty as an example of a big win for Track II diplomacy.”
  • Your conclusion states, “This is a proof of concept indicating that Track II diplomacy can have very large effects [my emphasis] on policies that are important for great power relations.”

On the other hand:

  • In the section on Claim 4 you say you think it’s equally likely that “political leaders would have agreed to limit ABMs regardless of whether they were convinced that the technology could be destabilising” and that “hearing scientists’ concerns would have been important for swaying political leaders to agree to ABM limitations.”
  • You later write that “If Pugwash participants ultimately influenced the policy outcome in the case of anti-ballistic missiles, it was because there was a window of opportunity for influence. The advocacy of respected scientists gave leaders additional reason to support a policy which they would already have been strongly disposed to favour because of other considerations.” This suggests to me something like, “Leaders were already >50% likely to support the policy, and Pugwash increased that likelihood but did not have a decisive impact on the policy being approved.”

More generally, it might be helpful to use probability ranges to clarify what you mean by phrases like ‘a good case that’ and ‘very large effects’, and to use quantitative modelling to try to reach a more precise estimate of Pugwash’s counterfactual impact.

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