The Origins of Non-Proliferation (Grand) Strategy in the United States and Great Britain

Earlier this year, The Strategy Bridge asked university and professional military education students to participate in our first annual writing contest by sending us their thoughts on strategy.

Now, we are pleased to present the winning essay from Richard J.E. Brown of King’s College London.

All strategies have origins; none are conceived wholly from scratch. This axiom holds true even for states’ most fundamental strategies; indeed, the grander and more foundational the strategy, the more deeply rooted its historical and cultural origins. Yet it can sometimes appear otherwise: new strategic realities can emerge, if not overnight, then in the space of, say, a fortnight, a month, or a year, and states can be left scrambling to articulate a coherent response. The advent of nuclear weaponry was one such instance. The bombings of Hiroshima and Nagasaki stand as a watershed to which historians and policy-makers are inexorably drawn. What came before stands as pre-history; what follows is a brave new world, demanding brave new strategic visions. So runs the logic.

Yet it can hardly be said that the policy-makers of late 1945 were composing policy tabula rasa. Rather, they were hemmed in on every side by obligations and compulsions which long predated the atomic bomb. As such, the historian’s penchant for watersheds, for fetishizing the iconic, symbolic moment of lost innocence or national destiny or whatever it might be labelled, can hardly be considered healthy—particularly if, as historians, we are fulfilling our task of analysing the past, rather than mythologizing it. Instead of treating 1945 as year zero for the western allies’ grand strategies, then, we must recognize that a radical shift in the assumptions underpinning military strategy was met, not with fresh thinking, but with the application of pre-existing concepts.

This paper seeks to address this tension, and to trace the origins of British and American strategies of nuclear non-proliferation to their proximate origins in the Second World War. It will be argued that the divergence of the two states’ Cold War attitudes to nuclear proliferation has to do with their differing wartime experiences of nuclear weapons development, and that these differing experiences were, in turn, rooted in longer-standing strategic cultures, in the American case, of independence of action, in the British, of imperial collaboration.

Non-Proliferation as a Grand Strategy

The emergence of nuclear weapons as factors in states’ strategic calculus was, in most instances, rather abrupt. For all but a handful of individuals in a handful of states, the weaponisation of uranium fission, demonstrated to such deadly effect over two cities in southern Japan, came as a complete surprise. In the weeks, months, years, and decades that followed, responses to a new military-strategic reality had to be articulated. Inaction could never be an appropriate response to the arrival in armed conflict of a weapon three orders of magnitude greater in destructive power than anything that had previously been deployed.[1] Even for the parties responsible—that is, the United States, aided and abetted by the United Kingdom and Canada—it became necessary to calculate the probable long-term import of the technology they had almost unwittingly unleashed on the world. That is to say, strategists of all nations were driven to develop concepts for responding to a profound change in their external security environments.

Left: Atomic bombing on Hiroshima on August 6, 1945. Right: Atomic bombing of Nagasaki on August 9, 1945. (Wikimedia)

The resulting strategies of response can be classed as grand strategies insofar as they can be considered to have become foundational articulations of the ultimate objectives of a state.[2] This can certainly be argued to have been the case in the United States. Francis Gavin, in a paper deserving of wider dissemination than it has thus far enjoyed, has argued that a strategy of nuclear inhibition has constituted a key element in US grand strategy since 1945. Gavin argues that nuclear policy and non-proliferation issues have their own logic, distinct from but related to other strategic impulses. Throughout the Cold War and into the present the idea of nuclear inhibition has been the third pillar of US grand strategy, alongside efforts to ensure (1) the containment of threats and (2) openness of global markets. This strategy of inhibition manifests itself in two ways. First, in the aggressive pursuit of nuclear primacy, and second, in a willingness to put pressure on other states—even on close allies—in order to prevent their developing nuclear forces of their own.[3] truly understand the logic of non-proliferation as a (grand) strategy, we must look to its origins, to the years before Hiroshima.

Gavin certainly has a point. The McMahon Act enacted by Congress in 1946, as the United States’ first concerted effort at post-war legislation on nuclear issues, seemingly embodied both principles perfectly.[4] As a piece of legislation the Act was demonstrably intended to deliver the maximum possible nuclear advantage to the US and to withhold information even from wartime allies. Its strict application in subsequent years, and even the few instances of loop-holes and work-arounds which were eventually found, all ultimately point to an underlying logic of exclusivity for the US on the one hand and inhibition of other states on the other. The same premise is evident even today, long after the act itself has ceased to be active. In accounting for American post-war policy, the Gavin thesis therefore seems fairly robust. Interestingly, though, Gavin never really touches on the actual origins of this American impulse to exclusivity and inhibition. Instead, he is implicitly reliant on an idea that this paper rejects—that of 1945 as a clean slate on which nuclear strategies could be written afresh. There is some very valuable material presented on the strategic logic of inhibition as a going concern, but nothing as to how it emerged, or whether it was somehow always present. In that sense, then, the Gavin thesis is perhaps somewhat incomplete: to truly understand the logic of non-proliferation as a (grand) strategy, we must look to its origins, to the years before Hiroshima.

The Wartime Experience

The Manhattan Project was not, despite appearances, a solely American effort. A significant number of British and Commonwealth personnel contributed to the programme, serving as part of officially sanctioned delegations in a range of crucial roles at Los Alamos and elsewhere.[5] The path to this ultimately successful collaboration was not, however, particularly straightforward. Co-operation with the British was never the default option for the United States, and there were vocal, influential opponents to the incorporation of foreign scientists at every stage. At no point was a desire to share nuclear knowledge with wartime allies apparent in any echelon of the US nuclear or military leadership. Incorporating the independent UK effort was neither easy nor intuitive.

Alumni of the creation of the first nuclear reactor, CP-1, at the University of Chicago's Metallurgical Laboratory. (Emilio Segrè Visual Archive)

For all its complexities, though, the story of wartime Anglo-American nuclear collaboration can be sketched concisely. The British and American nuclear programmes had had essentially independent origins. In both cases, the accelerating pace of research into uranium chemistry immediately prior to the war had prompted various individuals and groups to further explore the problem, in some cases with a degree of direct government sponsorship. (The same was true of other countries: France, Canada, and of course Germany). Owing partly to the stimulus of being joined by a number of émigré scientists, the British made rapid theoretical progress. A crash program of experimental work gave a strong indication that explosive nuclear fission would be both possible and, more to the point, militarily useful. These conclusions were shared with the Americans, whose programme had been meandering along rather more sedately. News of the British conclusions had a catalysing effect, as did the attack on Pearl Harbor in December 1941. Declarations of war tend to focus the official mind.

Exchanges between the two states continued at a modest level throughout 1941 and 1942. Experimental data was exchanged as a matter of course, and there were regular meetings to discuss new developments. In this period, however, the American programme began gradually to overhaul, and then outstrip, the British programme; so much so that in January 1943, with the American project now firmly in the hands of the United States Army, an attempt was made more thoroughly to marginalise the British programme. The rationale for this is the subject of some historical debate, with interpretations naturally varying somewhat between the two sides of the Atlantic, but what is clear from the British side of the archival record is the extent to which the Americans’ change of tack had come as a surprise.[6]

The British assumption, right from the outset, had been that there would be a joint approach on the part of the allies, perhaps relatively loose in terms of actual integration but reasonably free in terms of exchange. This had held true even as the American programme began to pull ahead: the British made the decision to invest, jointly with the Canadians, in a laboratory in Montreal, confident that the work there could be conducted in close collaboration with the US programme. Yet now the Americans were seemingly willing to walk away entirely from this apparent understanding. The Americans of course saw it very differently: in their view they were certainly not beholden to the British, and there seemed to be little to gain and much potentially to lose by allowing the British unfettered access to what was rapidly becoming the most important secret in the country.

Still, the strength of British protests, and the threat of their launching an independent programme, wholly outside American influence, prompted the Americans to reconsider. Through the summer of 1943 there were extensive and at times very fraught negotiations, which culminated in the Quebec Agreement, by which much of the UK programme would be subsumed into the American. Under the terms of the agreement the best qualified of the British scientists were dispatched to Los Alamos and Berkeley, while others pushed ahead with a supplementary experimental program in Canada. Under the scientific direction of J. Robert Oppenheimer, the combined efforts of the Manhattan Project, bolstered by the infusion of British expertise but still overwhelmingly American in its composition and direction, produced the world’s first nuclear device on 16th July 1945.

...the idea of nuclear inhibition pre-dated the realisation of the nuclear weapon.

What emerges from this brief account is the extent to which American attitudes embodied, more or less from the outset, aspects of Gavin’s concept of a strategy of inhibition. The Americans were never particularly keen, on an institutional level, to exchange nuclear information with the British, and many key individuals (Groves, Conant, Bush) were consistently reluctant to countenance any extension of collaboration beyond the levels imposed on them from above. Even where collaboration did take place—usually after judicious application of political influence by the British—the principle at work was that co-operation, even with close allies, was always to be transactional, and must, wherever possible, remain asymmetric; that is, in any given instance more must be gained by the United States than would be surrendered. In short, the idea of nuclear inhibition pre-dated the realisation of the nuclear weapon.

All of this serves also to highlight an interesting contrast between the Americans, with their already-apparent strategy of inhibition, and the British, whose attitude was almost exactly the reverse. Where the Americans sought independence, the British sought collaboration; where the Americans were chary of information exchange, the British actively embraced it. This cannot be explained simply by reference to the asymmetry of the two countries progress (though this was doubtless a factor at times), because the differing impulses were evident even in situations where the British held a technological advantage. Reference must instead be made to the differing strategic cultures of the two allies.

Independence and Empire as Strategic Paradigms

In seeking to explain the differences in nuclear policy it is important first to determine whether these examples were formative, in the sense of establishing expectations for all that followed, or whether they reflected an already existing impulse. That is, was it the wartime experience that began the process of entrenching nuclear inhibition as a cornerstone of American foreign policy, or were these incidents merely the first nuclear-era manifestations of some deeper American impulse? Was it the wartime realisation of the dividends obtainable from American cooperation that so inclined the British to nuclear trans-Atlanticism, or was some more fundamental impulse to collaborate at work?

As is so often the case in historical enquiry the answer seems somewhat ambiguously to lie between the two extremes. One could certainly argue that the Americans’ experience of collaboration with the British had not, on the whole, been a happy one. There had been tangible negative outcomes associated with the inclusion of non-American personnel in the Manhattan Project. One of the most conspicuous post-war justifications for American nuclear restrictions was the retrospective discovery of various ‘atom spies’ within the British team, including the physicists Klaus Fuchs and Alan Nunn May. The post-war discovery of their treachery precipitated the heightened security and sense of paranoia that subsequently dominated US nuclear policy-making.

William Penney, Otto Frisch, Rudolf Peierls, and John Cockroft. (Atomic Heritage Foundation)

Even before this, one can identify instances of American disquiet about the risks of espionage: the British team was never particularly British, and the Americans were never entirely comfortable with that fact. Many of the more prominent members were émigrés, and though many of them (Otto Frisch and Rudolf Peierls, for example) were swiftly naturalised there remained a strong thread of suspicion about them. The team at Montreal, meanwhile, included a number of Free Frenchmen, occupying very senior positions, whose behaviour towards the end of the war again deeply disturbed the American authorities.[7] More broadly, the British were, in American eyes, shockingly lax in their approach to security matters, and the British Dominions of Australia, Canada, and New Zealand, with whom the British had the reflexive habit of sharing significant amounts of very sensitive information, were laxer still. Thus even before the McMahon act—even before Hiroshima—one should not underestimate the extent to which Groves and company felt uncomfortable about UK model of easy transnational collaboration. Negative experiences of collaboration, incidents of treason and miscommunication, certainly reinforced the American’s inclination to secrecy and inhibition, but the germ of inhibition already lay within American strategic culture, and not within the British. The view from the eastern side of the Atlantic was entirely different.

Why so? The glib conventional answer would be simply to point to the industrial disparity between the two countries: the British knew that the US was better equipped for nuclear research, and so almost from the outset sought simply to hang on to American coat-tails. What the archive suggests, however, is something quite different. In British internal discussions, painstakingly minuted or recorded in hundreds upon hundreds of telegrammed memoranda, it emerges that the British assumption about how nuclear weapons development would work was initially predicated on their expectations as to how collaboration with an Anglophone ally might work. Their vision was of interaction with the Americans through a Commonwealth-style alliance structure. The haphazard, seemingly self-defeating course of British nuclear collaboration policy in the early part of the war actually makes most sense when seen as a partial misreading of the strategic reality of their alliance.

In the nuclear realm at least, the British seem to have mis-characterised the nature of the US relationship. Taking their cues from the dynamics of imperial defence and dominion relations, they assumed that the transatlantic alliance embodied greater unity of purpose, vision and ethos than was actually the case. The British took it for granted that a state with a shared heritage and similar values, speaking the same language and fighting the same foe, would embrace collaboration almost reflexively. On security issues, therefore, the British position was essentially that interchange with other trusted partners (i.e., the Dominions) was acceptable unless explicitly ruled out. The American position was very much the opposite. The same was true in other areas: the British felt no real reluctance in incorporating New Zealand scientists into their own nuclear research teams, and could therefore see no reason why the Americans should not incorporate British scientists into their research teams just as readily. Such reckless muddying of the waters of sovereignty was practically anathema to Americans raised in a sovereign state unencumbered with the constitutional complexities inherent in the British Empire’s convoluted internal politics.

The tension between British and American initial assumptions—with the principle of implied permission ranged against the principle of prohibition by default, and the principle of absolute solidarity ranged against the principle of absolute sovereignty—helps account for the fact that the American and British programmes drew very different conclusions from the same experiences. It was not simply about the post-conflict disparity in economic or military power: it was also about how the same raw material of interactions could be interpreted. Indeed it is interesting to note that it was above all the British experience of American inhibition efforts that reinforced the UK government’s desire for a model of possession-with-collaboration.

Conclusion: Nuclear History and Grand Strategy

The historical record clearly demonstrates that ostensibly closely-aligned states can nevertheless differ in terms of their core attitudes to non-proliferation, and further analysis shows that these differences arise from the interaction of empirical experience and more deep-seated assumptions about how the world works. Nuclear inhibition has been a significant strain in American grand strategy precisely because of the disenchanting experience of nuclear collaboration during the war, and its resonance with a latent worldview within the emerging nuclear establishment. The same wartime experiences had a very different effect on the subsequent policy of the United Kingdom, because the lens through which they were interpreted was different.

What is important here is the central role of analogy to past experience in the formation of new strategy, that is, the unavoidable impulse to interpret novelty in light of existing mental concepts. Recall, for example, that before their use in anger even well-briefed grand strategists like Churchill conceived of nuclear weapons simply as a higher-yield form of conventional explosive. The idea of a paradigm shift is a concept familiar enough to have become a cliché, even (perhaps especially) in the context of strategic studies.[8]

Yet in its original form, as outlined by Thomas Kuhn, the idea retains some explanatory power, if only by analogy. At any rate, the Kuhnian principle that novelty emerges only with difficulty, manifested by resistance, against a background provided by expectation seems readily applicable to the articulation of strategy in the early/pre-nuclear age.[9] The idea that there could exist some point at which the potential yield of this new weapon type might become sufficiently large as to fundamentally change the strategic calculus, so as to demand the revision of even the most entrenched strategic assumptions, was slow to emerge. No matter how dramatic the apparent watershed, in paradigmatic terms the process is always evolutionary, rather than revolutionary: the existing paradigm might ultimately be radically transformed, but it is always preceded by a last-ditch effort to conform the new development to the old thought system.

Thus, if the had Americans learnt anything from their uneasy collaboration with the British, it was that allies were awkward, unpredictable, and uncontrollable. Once information had passed outside the strict control of United States personnel, there could be no real assurance that it would be treated with the same extreme care that it would receive in American hands. As these attitudes were being formed there was a combination of existing impulse and experience at work. Groves, Conant and the other policymakers had always felt at least some discomfort that circumstances had drawn the two programmes into an initial position of regular exchange. Conditions in the US, and the particular security culture of the US Army, were not ordinarily amenable to foreign participation in sensitive projects. Yet the Americans had, against their better judgement, engaged in a multinational endeavour, and in their view had gained little and risked much by doing so. They were primed by circumstance to be suspicious of collaboration, and their immediate experience validated an existing worldview. Confirmation bias led them to downplay the positives and accentuate the negatives. The lesson to be drawn from this first foray into the nuclear world was that the joint programme had, on balance, been more trouble than it was worth.

The same prefiguring of post-war policy is evident in the British wartime experience—with almost the opposite conclusion, stemming from differing initial conditions. In particular, the early history of UK nuclear policy cannot be divorced from an understanding of the UK’s imperial-commonwealth connections. James Eayrs in his diplomatic history of Canada, presented the idea that Canada had grown up allied—that the nature of Canada’s slow evolution from colony to sovereignty placed her, from birth, within a default network of alliances.[10]

The concept could be extended right across the dominions of the British empire, including to Britain herself: gradually, in the course of the mid-twentieth century, the commonwealth ceased to be an entity of British dominance and instead became a kind of loose Britannic alliance structure. By the early years of the war, this seems to have become the default British attitude—that beyond Britain there lay a constellation of helpful Anglophone states with the same basic loyalties and the same basic impulses, who could be relied on as faithful ‘super-allies’. Here, again, the old paradigm was put to work in adapting to a new reality.

In all of this it is important to recognise the roots of grand strategy, and above all that such strategies invariably draw on previous experience.

None of this is to downplay the roles of individual leaders per se. Much of the course of American nuclear history was set by the decisions of headstrong individuals like General Leslie Groves. Yet even so exceptional a character as Groves cannot be divorced from his wider context. He was not the only such leader to shape Anglo-American defence collaborations in the twentieth century, and the pattern by which he enacted what he saw as strategic imperatives was not unique. Parallels might easily be drawn with the Royal Navy’s later experiences interacting with Hyman G. Rickover, the Father of the Nuclear Navy. Rickover was a man certainly capable of demonstrating Grovesian hauteur, with an independence of mind bordering, like Groves, on rank stubbornness.[11] Of course, parallel lines by their nature never intersect, whereas Groves’ and Rickover’s careers certainly did. Both were, in the historiographical sense, great men, figures of substantial influence. Both, however, were reading from a script that had already, to some extent, been written: that they improvised effectively through the lacunae is not evidence that in some instances—perhaps, indeed, in all instances to some degree—they were acting as circumstances (that is, the dominant paradigm, the operative grand strategy) dictated. Groves’ leadership, like Rickover’s, like all leaders’, was conditioned not simply by personal influences (in Groves’ case, inherited Anglophobia and professional ambition), but also, more foundationally, by the strategic cultural impulses absorbed, unwittingly, in the course of a long career.[12]

General Leslie Groves and Dr. Robert Oppenheimer at the site of the Trinity test in September 1945. The white overshoes were to prevent fallout from sticking to the soles of their shoes. (U.S. Army Corps of Engineers/Wikimedia)

In all of this it is important to recognise the roots of grand strategy, and above all that such strategies invariably draw on previous experience. This holds true even in the context of apparently dramatic paradigm shifts. Events, and the experience of events, form the data from which future policies are constructed, and experience is mediated by worldview—by assumptions, which are culturally conditioned. Strategies do not form in a vacuum. Rather, they are the product of a continuous process of old paradigms coming into conflict with new experiences and thereby being re-forged. In that sense the evolution of grand strategy is the history of existing assumptions interacting with new experience.

Richard Brown is a PhD candidate in the War Studies Department, King’s College London. He also serves as a research associate on a project in support of the international nuclear non-proliferation regime, pursuing research on Middle Eastern states’ nascent nuclear capabilities. A graduate of the University of Oxford and King’s College London, his doctoral research focuses on the confluences of 20th century diplomatic, strategic, imperial, and nuclear history.

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Header Image: A U.S. Air Force B-2 Spirit bomber aircraft from Whiteman Air Force Base. (USAF Photo/A1C Joel Pfiester)


[1] The ‘Grand Slam’ seismic bomb developed and deployed by the RAF had 1/2000th the yield of the ‘Little Boy’ device used at Hiroshima. Grand Slam had previously been, in explosive terms, the most powerful weapon deployed in the conflict.

[2] This clearly only applies to a handful of states – that is, those states whose existence and/or interests are conceived as bound to, or threatened by, the existence of rival powers capable of challenging them. For the most part, this category coincides with those states which are conventionally considered ‘great powers’.

[3] Gavin, Francis J., ‘Strategies of Inhibition: U.S. Grand Strategy, the Nuclear Revolution, and Nonproliferation’, International Security 40:1, 2015.

[4] Atomic Energy Act of 1946 (Public Law 585, 79th Congress) <>

[5] For the work at Los Alamos see Szasz, Ferenc Morton, British Scientists and the Manhattan Project, (Macmillan, 1992); on the British program more widely, see Gowing, Margaret, Britain and Atomic Energy 1939-1945 (Macmillan, 1964). The substantial contribution of the British group to the electromagnetic separation work at Berkeley awaits its historian, but a significant volume of relevant information on their activities can be found in files AB 1/2 and AB 1/198 in The National Archives of the UK (TNA).

[6] cf. correspondence series from 2nd January 1943 onwards in AB 1/374 (TNA). The American case is put most clearly in Hewlett, Richard G., & Anderson, Jr., Oscar E., A History of the United States Atomic Energy Commission, Volume I, The New World, 1939-1946, (Pennsylvania State University Press, 1962).

[7] cf. Cockcroft to Chadwick, 21st December 1944, AB 1/193 (TNA), and Akers to Perrin, 24th January 1944, AB 1/113 (TNA). The AB 1 series more generally contains vast amounts of material on Anglo-American nuclear interactions during and immediately after the war.

[8] Freedman, Lawrence, Strategy: A History, (OUP, 2013) p.421

[9] Kuhn, Thomas, The Stucture of Scientific Revolutions, (University of Chicago Press, 1996) p.64

[10] Eayrs, James, In Defence of Canada: Peacemaking and Deterrence, (University of Toronto Press, 1972)

[11] Jinks, James, and Hennessy, Peter, The Silent Deep: The Royal Navy Submarine Service Since 1945, (Allen Lane, 2015) pp.141-2, 188-91

[12] ‘‘Anglophobia ran deep in the Groves family’; Norris, Robert S.  Racing for the Bomb: General Leslie R. Groves, the Manhattan Project’s Indispensable Man, (Steerforth Press, 2002) p.3