Toshihiro Higuchi. Journal of Strategic Studies. Volume 29, Issue 1, 2006.

On 19 July 1956, upon his return from the Pacific Eniwetak Proving Grounds in the Marshall Islands, Atomic Energy Commission (AEC) Chairman Lewis L. Strauss issued a press release. As usual, it was nothing but a series of the familiar platitudes about the ‘success’ of Operation ‘Redwing’, the current nuclear testing series. What attracted unusual attention—and a barrage of questions and derision later—was a remark by Strauss about an ‘achievement of maximum effect in the immediate area of a target with minimum widespread fallout hazard’. This success, according to the AEC chairman, made the current testing series ‘of importance not only from a military point of view but from a humanitarian aspect’. Strauss’ statement seemed to be no more than another bad joke in the thermonuclear age. A typical response was provided in a mode of irony. ‘Part of the madness of our time is that adult men can use a word like humanitarian to describe an H-bomb’, a scientist commented.

And perhaps we, now in the aftermath of the Cold War, find no difficulty in ridiculing this ‘clean’ bomb. Chuck Hansen, a military historian who has meticulously traced the story of the clean bomb, concludes that ‘clean’ weapons were ‘primarily just an expensive public relations gimmick’, aside from being an interesting technological challenge. Perhaps he is right. With hindsight, a clean weapon seems like something in Dr Strangelove’s bizarre inventory. It seems a weapon for propaganda war, not for any real war. And it seems to offer a good example for us to ponder how much the words ‘humanitarian’ and ‘clean’ had become contaminated by the excessive dust from nuclear testing.

Strauss, however, did not intend to entertain philosophers or literary critics. As he clearly stated, a clean bomb was important ‘from a military point of view’ as well as from a ‘humanitarian aspect’. In his mind, it was as much a military weapon as a propaganda weapon. And as a military weapon, it was supposed to claim a legitimate place in US nuclear strategy. This article, therefore, will reexamine the clean bombs episode within the context of the development of nuclear weapons and nuclear strategy during the Eisenhower years. This reexamination seems warranted, as the period when the possibility of clean bombs was vigorously pursued and hotly disputed corresponded with the period in which nuclear strategy underwent a serious reassessment in public as well as in the circle of policymakers in Washington. A close investigation of the clean bomb story will illustrate the dynamic interactions between nuclear technology and nuclear strategy, both of which were designed, contested, and transformed, in response to their inner mechanism of maximizing its rationality as well as external factors surrounding them, including the politics and ‘culture’ of the military, civilian bureaucrats, scientists and engineers.

In discussing the relationship between nuclear technology and nuclear strategy, I will shed light upon some important insider nuclear strategists. In particular, the odyssey of John Foster Dulles, President Dwight D. Eisenhower’s secretary of state and allegedly a chief architect of the massive retaliation nuclear strategy, will demonstrate how people other than ‘professionals’ often shaped nuclear strategy and how agendas other than military ones guided it. Also interesting is Captain John H. Morse, Jr., Strauss’ right-hand man in the AEC, who vigorously advocated the development of clean bombs in his design of a post-massive-retaliation nuclear strategy.

The clean bomb controversy also provides us with an interesting insight into the question of why and how US nuclear testing continued until 1958. As many scholars have argued, clean bombs came under the spotlight primarily as a propaganda tool to justify the continuance of nuclear testing. As dread of radioactive fallout, highlighted by the Bikini incident in 1954, fueled public opposition to nuclear testing, clean bombs could have been an effective instrument to combat such a fear. By illustrating how clean weapons turned into a propaganda weapon, I will trace many threads which became interwoven and perpetuated the self-sustaining process of nuclear testing.

New look at fallout, second thought to strategy: The bikini incident

Operation ‘Castle’ unleashed a radiological nightmare. On 1 March 1954, at the first grey of dawn, the Pacific sky over the Marshall Islands was suddenly brightened up by another sun—Shot ‘Bravo’, which successfully detonated the ‘Shrimp’ device, the first US usable hydrogen bomb. Everything to trigger the contamination havoc was there. The yield was 15 megaton TNT-equivalent [MT], twice as much as scientists had predicted. Detonated with such a sheer force at as low as 7 feet above the reef, the fireball of ‘Bravo’ gouged a crater more than 6,000 feet wide and over 200 feet deep, vaporizing 61 tons of steel and 18½ tons of wood, along with nearly 81 million cubic yards of coral sand and rock. Sucked up into the fireball and touched by high-speed neutrons, this massive volume of material was induced into radioactivity. In addition, the dangerous radioactive debris also came from the fission part of the device. Although it was regarded as a hydrogen bomb, ‘Bravo’ comprised a so-called ‘3F process’: primary fission, secondary fusion, and tertiary fission. In this system, the primary fission device, once detonated, creates a very high temperature sufficient to trigger the fusion (thermonuclear) reaction at the secondary stage. The major source of energy in the 3F process, however, comes from the tertiary fission device that wraps the fusion device. Bombarded by massive numbers of neutrons with extremely high kinetic energy created by the fusion reaction, the material surrounding the secondary device, which is otherwise hardly fissionable, splits and adds tremendous power to the weapon. Indeed, two-thirds of ‘Bravos’s’ total yield came from fission, not fusion. Yet another factor completed the nightmare. A sudden shift of wind blew the radioactive fallout toward the populated islands. Soon, ‘ashes of death’ poured onto American soldiers, Marshallese people, and Japanese fishermen.

Shot ‘Bravo’ was by no means the first case of radioactive hazard accompanying US nuclear tests. The danger received public attention when Shot ‘Baker’ in 1946 blew up and contaminated thousands of tons of water with a massive volume of coral reefs. The Pacific Ocean was not the only place for radioactive contamination. In 1953, Operation ‘Upshot-Knothole’, conducted in the Nevada Test Site, generated dirty radioactive mushroom clouds, later connected to the death of sheep in Utah and the detection of unusual levels of radioactivity as far as in New York State. Therefore, ‘Bravo’s’ incident was not a unique one. It was, however, distinguished from any previous case in other contexts. First, ‘Bravo’ was the first case which illustrated the unprecedented extent of local radioactive hazard caused by a hydrogen bomb. Any nuclear weapon yields its energy in three forms: thermal radiation (heat), kinetic power (blast), and radiation (neutrons, Alpha, Beta, and Gamma rays). A 20 kiloton TNT-equivalent [KT] pure-fission bomb scatters lethal radiation to several miles from ground zero, not much beyond the distance of heat and blast effects. A 10 MT standard hydrogen bomb, on the other hand, expands the range of its heavy local fallout to over 125 miles. “Bravo” clearly demonstrated that radioactive fallout by a high-yield hydrogen bomb was not merely a ‘bonus effect’ any more. British Prime Minister Winston Churchill’s imagination aptly captured this point. In his letter to Eisenhower in March 1954, he mentioned an ‘ugly idea’, the dropping of a hydrogen bomb in the sea to windward of the British Isles or any other seaborne country: ‘The explosion would generate an enormous radio-active cloud, many square miles in extent, which would drift over the land attacked and extinguish human life over very large areas. Our small size and density of population emphasises this danger to us.’ Fallout emerged as a potential tool to inflict indiscriminate death, far beyond the scope of destruction by heat and blast.

Second, the effects of radioactive fallout were not limited to immediate and local areas. The mushroom cloud of a hydrogen bomb can reach into the stratosphere, and radioactive particles with long decay life can fall anywhere on the earth. This worldwide long-term effect soon evoked great scientific attention as well as public outcry, especially with regard to the uncertain genetic effects of fallout. As any small increase of fallout might trigger a genetic effect, nuclear detonations in peacetime—nuclear testing—could threaten the existence of human beings. Fallout thus became a symbol of the nuclear danger in the Cold War.

The effects of fallout from ‘Bravo’ themselves were sufficient to precipitate public hysteria and strain US foreign relations, especially with Japan. But ‘Bravo’s nightmare—and the fallout problem—cannot be fully understood apart from its context of nuclear strategy. Actually, from the strict point of view of nuclear strategy, ‘Bravo’ was highly successful, as it laid the solid technological basis for the doctrine of massive retaliation. Just two months before ‘Bravo’, Secretary of State Dulles had unveiled the concept as the Eisenhower administration’s nuclear strategy. Although Dulles’ presentation contained more nuance than his contemporaries perceived, the crux of massive retaliation was still a disproportional response to the enemy’s aggression aimed at inflicting instant and utter destruction upon the enemy. This action could hardly be carried out without a hydrogen bomb whose power and scope was theoretically infinite. The bigger and more destructive a nuclear weapon became, the higher the price of aggression an enemy had to pay, and therefore the stronger the deterrence became. And the more efficient and economical the use of nuclear materials became, the more nuclear weapons would be available for massive and instant retaliation. This logic of massive retaliation, already established before the strategy was announced, had long guided the direction of nuclear testing before ‘Bravo’. President Eisenhower’s announcement on Operation ‘Castle’ vividly illustrated this point:

The explosive yield from a device recently tested has been greater than that of any previously detonated. This is in accord with the record of previous test series, each of which has regularly surpassed the results of earlier ones. Our constant aim is to obtain the maximum efficiency possible from nuclear material.

Furthermore, the military always demanded a higher yield of nuclear weapons to ensure the total destruction of targets with a smaller number of delivery vehicles and even with large bombing errors. As the price tag for the development, deployment, and maintenance of state-of-the-art missiles and aircraft became higher, a more destructive weapon seemed all the more desirable. And the efficient use of fissionable materials promised a cheap bang for the buck. As Operation ‘Castle’ proved that even ordinary lithium hydride could be used as hydrogen bomb fuel, the amount of fusionable materials required to yield a ton of TNT-equivalent explosive power, was estimated to cost only 10¢, compared to approximately US$500 for a ton of TNT. In short, not just the massive retaliation doctrine but the whole ‘New Look’ national security policy rested on the promise of the nuclear plenty ‘Bravo’ heralded.

If ‘Bravo’ fulfilled the technological conditions for massive retaliation as a strategy, it began to erode the political underpinning of the strategy. Hearing the bang of ‘Bravo’, US foreign allies seemed to run away. The tiny island the hydrogen bomb wiped out had an ominous analogy to small island countries like Japan and the UK. ‘Japan and England are upset’, Dulles told Strauss. ‘Bravo’ seemed to embody the scenario of massive retaliation Dulles had brandished just recently. ‘It is driving our Allies away from us’, he said. ‘They think we are getting ready for a war of this kind…. It could lead to a policy of neutrality or appeasement.’

As a solution, Dulles suggested a possible moratorium on hydrogen bomb testing. Strauss and Defense Secretary Charles Wilson strongly opposed a moratorium, basing their arguments on the technological and militarily necessity of weapons’ improvement through nuclear testing. To Dulles, however, the cohesion of the Western alliance was even more important than nuclear weapons to wage the Cold War over the long haul. ‘We could not sit here in Washington and develop bigger bombs without any regard for the impact of these developments on world opinion’, he said. ‘In the long run it isn’t only bombs that win wars, but having public opinion on your side.’ A bigger bomb, which laid the basis for the massive retaliation strategy and the balanced budget, now began to endanger the solidarity of Free World and cast doubt on US moral standing in the eyes of world public opinion. Something should be done before the US was left without an ally, only with bigger bombs.

Clean bombs: A technological solution to a political question

‘Bravo’ raised questions not only about nuclear strategy and morality in the thermonuclear age, but also about the direction of nuclear weapons development, which had been so far guided by the clear-cut mission of making a hydrogen bomb. As ‘Bravo’ completed the mission, the atomic scientists suddenly lost self-evident guidance. It seemed to them that, now with both fission and fusion exploited, the future would bring only small additional increases in the explosive power per ton of nuclear bombs. Dr Norris E. Bradbury, the director of Los Alamos Scientific Laboratory (LASL), soberly pointed out this gloomy future for nuclear weapons development, and for his laboratory:

Although the developmental demands upon the Laboratory [sic] are very heavy today and five or ten years of very hard work can be foreseen, the future beyond that point looks somewhat unrewarding. Fissionable material will go on and on being made until the efficiency of atomic weapons will become of academic interest. Everyone will ultimately have all the weapons in all the variety wanted, and the number will probably be more than the world can safely tolerate being used. […] there does not appear to be any unscaled peak on the horizon in 1955 comparable to the challenge of a thermonuclear weapon a decade ago. In all frankness, the things the weapons laboratories are now doing and foresee doing are modifications, variants, and extensions of basic ideas going back, in some cases, many years.

This pessimistic view, however, was not shared by atomic scientists at the University of California Radiological Laboratory at Livermore (UCRL). Dr Herbert York, its director, pronounced the ‘working philosophy’ for this newly established laboratory in 1952:

Our working philosophy, which I set out at the very beginning and which everyone readily accepted, called for always pushing at the technological extremes. We did not wait for higher government or military authorities to tell us what they wanted and only then seek to supply it. Instead, we set out from the start to construct nuclear explosive devices that had the smallest diameter, the lightest weight, the least investment in rare materials, or the highest yield-to-weight ratio or that otherwise carried the state of the art beyond the currently explored frontiers. We were completely confident that the military would find a use for our product after we proved it [their invention].

This working philosophy embodied a prototype of many scientists’ responses to the post-‘Bravo’ circumstances. They found in the technological extremes their personal excitement and intellectual stimulus. They firmly believed that the relentless pursuit of such extremes was the best way to win the nuclear arms race by quality and assure American nuclear superiority. And they knew that they should be good salesmen as much as good scientists in lobbying for their commodity—nuclear weapons technology. Furthermore, their venture toward the technological extremes was fueled by the keen rivalry between the two laboratories, which by itself seemed sufficient to define the UCRL’s objectives ‘essentially as to do something more risky than Los Alamos [was doing]’. As ‘Bravo’ marked the end of the past rationale for nuclear weapons research, many atomic scientists, including those at the UCRL, were desperate to find fresh guidance for their technological mission, and to justify their own existence and service to the nation.

‘Bravo’ and its radiological accident hinted at such a new direction. The policymakers and military planners in Washington were anxious to find an answer to the question of radioactive fallout and to explore a solution to the problem of massive retaliation. An answer atomic scientists proposed was to clean up a hydrogen bomb by reducing the amount of radioactive fallout per yield. In April 1954, as early as one month after ‘Bravo’, the LASL prepared a preliminary study on how to decrease fallout. One simple way was to eliminate fission at the tertiary stage by replacing part or all of the natural and depleted uranium with non-fissionable material, such as lead. This method would reduce radioactive debris coming from the fission part of the bomb. It would also, however, reduce the yield of the bomb, since a conventional type of a hydrogen bomb gained much power from the tertiary stage of fission, as ‘Bravo’ had displayed. It was also a setback for a goal of a ‘cheap bang for the buck’, as the non-fissionable material would yield no power but simply make the bomb weigh as much as with fissionable material. Without a technological innovation, cleaning up the bomb would contradict the pre-‘Bravo’ goals of making a nuclear weapon more efficient and destructive. ‘Clean’ bombs, therefore, posed an important technological challenge for the atomic scientists.

‘Bravo’ also stimulated military interest in radioactive fallout. Until ‘Bravo’, US military planners had focused on blast effects, and had seen the effects of nuclear weapons more or less as an extension of conventional weapons. The military had therefore been preoccupied by the means of maximizing these blast effects. As blast effect correlated with yield, the military had consistently called upon atomic scientists for a bigger bomb. The effect was also dependent upon an operational situation for nuclear weapons. According to a US government study about the effects of nuclear weapons, a ground burst was the optimum choice for maximizing blast effects. This choice, however, also maximized the amount of induced radioactive fallout from soil. ‘Bravo’ and its radiological upheaval put into serious question the military’s simple call for the maximization of the blast effects by making a bigger bomb and detonating it close to the earth.

Fallout effects now loomed large in nuclear use scenarios. The strength and longevity of substantial radioactivity introduced the time factor into military planning. Lethal radiation could blanket such a vast area and its dissemination was so unpredictable that the military had to carefully weigh the damage to friendly as well as enemy installations in their use of high-yield nuclear weapons. This new factor, however, also seemed to be advantageous in certain military situations, such as to deny the enemy’s reentry into a large field by scattering specific isotopes from the bomb. After September 1954, the Defense Department repeatedly communicated to the AEC its strong interest in the radioactive contamination problem and noted the necessity of inventing methods of both increasing and decreasing the radioactive fallout from thermonuclear weapons. In response, by early January, 1955, both the LASL and UCRL submitted memoranda of their theoretical studies about ‘clean’ and ‘dirty’ weapons to the Defense Department.

Seeing growing military interest in controlling radioactivity, some AEC officials took the initiative to encourage their scientists. Among them was Brigadier General K. E. Fields, the director of Division of Military Application, who visited Berkeley and Livermore in early 1955 and discussed clean bombs with UCRL scientists. Upon his return to Washington, he sent a letter to York, urging the UCRL to ‘submit a proposal as to possible early realignment of your program toward a major effort in the field of clean weapons’. To prove feasibility, the UCRL would be allowed to conduct a nuclear test for this purpose in Operation ‘Redwing’, scheduled in 1956. Since this was an entirely new field of technological development, the AEC believed that ‘the gamble can and should be accepted’. This instruction must have delighted atomic scientists who had waited for a new call for their service to the nation after ‘Bravo’.

Not all scientists, however, were enthusiastic about this new guidance. The difference between the two groups was exposed in April when the AEC Washington office asked both the LASL and UCRL about their present understanding and prospects with regard to clean weapons. Bradbury of the LASL in his reply qualified his optimism for the weapons, by saying ‘we are not yet in a position to lay down a design of such a device’. Furthermore, the list of the objects to be tested in Operation ‘Redwing’ merely to meet the current demands for immediate military requirements had been already ‘impressively long’. Therefore, he was rather ‘reluctant to consider adding to this list if that can be avoided’.

On the other hand, the reply from the UCRL was upbeat about rapid progress in ‘clean’ technology. It raised a possible method of gaining a higher compression of the fusion stage by inserting an intermediate stage between the primary and the original secondary and creating a new three-stage device. The new secondary device would explode with a force of several hundred KT, and act as an x-ray emitter to trigger the highly-compressive reaction of the main fusion fuel at the tertiary stage. The high-energy neutrons would be contained by a non-fissionable heavy metal surrounding the secondary and tertiary devices to enhance the fusion reaction. In this way, the UCRL suggested a mechanism to reduce fission and maximize fusion, resulting in substantially reduced radioactive fallout from the bomb. It frankly admitted, however, that this idea was a preliminary one, and its main research efforts would remain concerned with an experimental device which could not be immediately and easily converted into a weapon.

Its reservations notwithstanding, the passion for clean bombs was clear in this UCRL reply. Buttressing this passion was its ‘working philosophy’. A goal of making ‘clean’ bombs was a call for a technological extreme of the fusion technology. It might have been all the more appealing because the UCRL, born out of intensive political lobbying by Dr Edward Teller, the physicist labeled as the father of H-bomb, had declared in its own statement of purpose a strong emphasis on long-term objectives and thermonuclear technology, as compared to the LASL’s alleged bias toward fission technology and immediate objectives. As the hydrogen bomb came under severe criticism for its massive radioactive fallout, Teller and his colleagues at the UCRL scrambled to save the scientific giant’s achievement by cleaning it up.

‘Redwing’: Clean bombs and public controversy

Two ‘clean’ suns rose up in the predawn sky over the Eniwetak Proving Ground in 1956. Shot ‘Zuni’, testing a device designed by the UCRL, was detonated on 28 May 1956. Using an inactive lead tamper to wrap the thermonuclear third stage, it yielded 3.5 MT, more than 80 per cent of whose total yield came from fusion. It also marked success for the first thermonuclear device design ever tested by the UCRL. This success was, however, tainted by the fact that ‘Zuni’, detonated too close to the ground, scorched the earth and blew up some three million cubic yards of rock and coral into air, leaving a half mile crater at ground zero. Despite the small amount of fallout derived from fission, a massive volume of induced radioactive fallout scattered over 17,000 square miles.

Furthermore, ‘Zuni’ was not an innocent child of the clean technology, but a twin brother of its dirty version, Shot ‘Tewa’, detonated on 21 July. ‘Tewa’ had a uranium tamper around the tertiary stage instead of the lead tamper, and more than 80 per cent of its 5 MT yield came from fission, the highest known fission yield in any US thermonuclear test.

Another clean test, Shot ‘Navajo’, was designed by the LASL as a clean version of a TX-21C thermonuclear device. Exploded on 11 July 1956, it released approximately 4.5 MT. Its astonishing ‘cleanness’—as much as 95 per cent of the total yield came from fusion—overshadowed its rival, ‘Zuni’. This success, however, had its own downside. Whereas a standard version of TX-21C, with 60 per cent fission, could yield 10 MT, its clean version had only a half of the original yield. This result was far from satisfying, as it meant a significant loss in yield and efficiency. In short, the ‘success’ of the clean bombs in Operation ‘Redwing’ was at most a qualified one.

However qualified ‘Redwing’s’ technological success, it did not prevent the policymakers in Washington from exploiting it. Since ‘Bravo’, they had struggled with people’s fear of a doomsday scenario of massive retaliation, and their concerns about worldwide radioactive contamination from continued nuclear testing. Two factors thrust this struggle onto a different stage in 1956. The first one came from outside the government. The test ban issue, having already shaken US foreign relations, was introduced into domestic politics by Democratic presidential candidate Adlai E. Stevenson. Riding on popular anxiety and the division of scientific opinions about the genetic effects of fallout, he became vociferous in demanding a ban on testing hydrogen bombs.

The second one came from an insider. On 25 June 1956, Army Lieutenant General James M. Gavin told a Senate subcommittee that full-scale nuclear attack on the Soviet Union would cause tremendous collateral damage to friendly countries by deadly radioactive fallout. Army and other Defense officials rushed to prevent the publication of this secret testimony, but in vain. Republican Senator Henry M. Jackson, a member of the subcommittee, was ‘shocked’ at the publication, ‘not from the standpoint of security but from the standpoint of our friends throughout the world’. What Gavin revealed, however, was the already known disaster that would inevitably result from the massive retaliation doctrine, indicated by the ‘Bravo’ havoc. And it was a candid confirmation that policymakers as well as military planners had failed to find an alternative to non-discriminatory, wholesale destruction promised by their current nuclear strategy.

Instigated by Stevenson and Gavin, the public uproar against the test and use of hydrogen bombs gained new momentum and came to the center of politics. To supply fresh ammunition for the government, the AEC immediately drew up a press release to highlight the government’s efforts to control a nuclear disaster by inventing a clean bomb. The scientists, however, were reluctant to use their clean technology for such a propaganda purpose. Bradbury, for instance, ‘personally prefer[red] very strongly to withold any such statement’ until the scientists examined the debris from Shot ‘Zuni’, compared it to a standard version of a hydrogen bomb, and assessed the risk of disclosing the clean technology to the Russians. Teller also harbored some concerns about a possible disclosure of the clean technology. With his usual political savvy, however, he shrewdly sensed the direction of the political winds blowing from Washington. ‘There is indeed considerable pressure to stop A-bomb testing and even more to stop H-bomb testing’, he wrote to the AEC. ‘I feel strongly that all types of tests must continue. Therefore it is important to publish valid arguments for the test program.’

In Washington, however, hesitation prevailed. Commissioner Willard Libby, the only atomic scientist among the five AEC commissioners at the time, strongly opposed the proposed announcement, seeing the statement as a serious release of weapons design. He believed that the clean bomb was a ‘major new discovery’, despite ‘what Edward Teller says’. Brigadier General Alfred D. Starbird, succeeding General Fields in 1955 as director of the Military Application Division, voiced his concerns from a political point of view. Once the US highlighted the existence of clean bombs, ‘pressure would come from the United Nations or other sources to limit tests in the future to “Clean Weapons”’. Although Operation ‘Redwing’ recorded the successful beginning of the clean bomb development, the clean weapons at this point were still inefficient, heavy, and big. If a political and moral limitation of nuclear testing was imposed upon the US, it would seriously handicap many other development goals, such as a small, light and powerful intercontinental ballistic missile (ICBM) warhead. And if public pressure went further to force the government to limit its stockpile of high-yield nuclear weapons to the clean design, it would significantly reduce the power of the US nuclear strategic force.

As Gavin and Stevenson’s agitation picked up steam in July, however, the AEC was put under heavy pressure from politicians to do something. Harold A. Stassen, the President’s adviser for disarmament affairs, reported the rapid surge of clamor among world opinion about fallout. A possible revival of the havoc unleashed by ‘Bravo’ alarmed Dulles and Eisenhower, precipitating them to explore a fresh argument to justify the US position against a test ban. Eisenhower, however, did not wish to make the announcement by himself, fearing that he could not handle technical questions in front of the press. Dulles then asked Strauss to issue the statement. Strauss agreed to be a scapegoat to rescue the nuclear testing policy and nuclear strategy from the trouble. Under his name, the ‘humanitarian’ hydrogen bomb statement was issued on 19 July, attracting all the anger and ridicule. His earnest desire notwithstanding, his statement fueled, rather than defused, the controversy over radioactive fallout, nuclear testing, and nuclear strategy.

The biggest bomb, but ‘clean’: Massive retaliation and clean bombs

Although Eisenhower let Strauss inaugurate a clean bomb, he had by himself pronounced at the 25 April press conference the major justification for post-‘Bravo’ nuclear weapons development:

We go ahead with this hydrogen bomb—not to make a bigger bang, not to cause more destruction—to find out ways and means in which you can limit it, make it useful in defensive purposes, of shooting against a fleet of airplanes that are coming over, to reduce fallout, to make it more of a military weapon and less one just of mass destruction. We know we can make them big. We are not interested in that any more.

Clean bombs neatly fit into such a line of justification. With their significantly reduced fallout, they symbolized the new phase of nuclear testing after ‘Bravo’, aimed at controlling and disciplining a massively destructive hydrogen monster, which had once seemed to be incommensurate with any reasonable political goal or military consideration. The availability of clean weapons would provide the US with more options of response to aggression, and thus restore the original sense of ‘policy’ and ‘military’ in nuclear warfare. Many in Washington hoped that the clean technology would make a hydrogen bomb just another ‘military weapon’, and make a nuclear war once again reasonable, if not winnable, at least under certain circumstances.

Some scientists and military planners intended the clean technology as a technological way to preserve the momentum toward a bigger weapon and advance—not reverse—the logic of massive retaliation which had governed nuclear strategy and nuclear technology before ‘Bravo’. As the technological feasibility of the clean technology had been proven during Operation ‘Redwing’, the question of whether the US should make a bigger clean bomb became a major field of contention among scientists, military, and politicians. Its implications, in turn, extended to the question of nuclear strategy.

On 10 October 1956, the AEC sent a letter to the Department of Defense (DOD), informing it that the currently stockpiled TX-21 thermonuclear weapons, which weighed 17,500 pounds and yielded 10 MT, were ready to be converted into their clean versions with reduced fallout and yield. Furthermore, as a result of Operation ‘Redwing’, the AEC expressed its confidence at the prospect of developing a clean version of each high-yield category nuclear weapon: Class A, Class B, and Class C. With limited research resources and fusion materials, however, it urged the DOD to provide the military guidance for the priority between ‘standard’ weapons and ‘clean’ weapons, and between each category.

What the AEC emphasized in its communication with the DOD was its strong interest in the clean version of Class A and B weapons. To be sure, behind this bias toward a larger-yield category lay much technological difficulty in making a smaller clean bomb. Given the current level of technology, a large, powerful primary device was required to compress the fusion fuel and give to it sufficient heat and neutrons to burn. And the unfavorable weight-to-yield ratio of a clean bomb might be even more problematic for thermonuclear weapons of lower weight; below a certain limit, a clean version might not be possible at all.

The technological dimension, however, cannot fully explain this bias. First, there was considerable interference by the UCRL. With their ‘working philosophy’ of seeking the technological extremes, Teller, York and other scientists at the UCRL had long been lobbying for a bigger bomb than any other ever built by the US—one with a yield of over 20 MT. It was perhaps no coincidence that the UCRL would eventually be assigned to Class A and B weapons developments, the two highest-yield categories of nuclear weapons, after Operation ‘Redwing’. As high-yield hydrogen bombs earned a bad reputation with their enormous fallout, cleaning them up would supposedly make them militarily and politically usable, and thus justify the UCRL’s drive toward making the biggest bomb the world had ever seen.

Second, there was constant pressure from the military toward a bigger bomb even after ‘Bravo’ created a 15 MT weapon of mass destruction. According to the explanation put forward by the military, a very large clean bomb was necessary. This would ensure the total destruction of hard military targets in border areas between friendly and hostile territory, without generating excessive local fallout onto friendly territory. It was desirable also from an economic point of view, as the latest delivery vehicles, such as ICBMs and supersonic strategic bombers, cost more and more. And above all, the military argued, a bigger bomb would continue to be an important instrument to retain US deterrent capability under a limited defense budget and with diminished military personnel. Despite growing criticism inside and outside the government, the Pentagon still firmly embraced the logic of massive retaliation. The clean technology, therefore, seemed to enable them to continue to call for a bigger bomb and preserve the momentum of the ‘New Look’ strategy.

This seemingly consistent attitude of the military toward a bigger bomb, however, was far from logical or inevitable. It was rather a structural one, deeply embedded in nuclear war planning since the beginning of the atomic age. John H. Morse, Strauss’s special assistant, detailed this point in his memoranda sent to Strauss, referring to his previous experience of planning an atomic war under SACEUR (Supreme Allied Commander, Europe). According to Morse, the dividing line was currently running between the Army on the one hand and the Navy and the Air Force on the other over the question of very high-yield weapons. The Army opposed any very high-yield weapons development, either ‘clean’ or ‘standard’. The Air Force and Navy, however, pressed for so-called 60 MT weapons development, even without waiting for their clean configurations. The mechanism to generate military requirements for the numbers and types of nuclear weapons, however, had been dominated by the Air Force, especially the Strategic Air Command (SAC). This dominance, in turn, allowed the Air Force and SAC to channel all nuclear weapons development toward the ‘Sunday punch’—massive and instant strategic bombing on Russia—and thus to demand the largest possible weapons compatible with their big bombers. ‘Only strenuous efforts by a few Navy experts, supported by even fewer from the Army’, Morse argued, ‘diverted some effort toward putting this yield into smaller packages’.

The Air Force dominance also shaped nuclear war planning, and the consequent ‘requirements’ for nuclear weapons. ‘Air and Army atomic planners represent extremes which tend to generate excesses’, Morse explained. ‘Air planners think in terms of facility destruction—people are incidental. Army planners think of men—facilities are incidental’. As weapons effects tests tended to provide specific data for installed facilities rather than for unpredictable men, the Army had few reliable figures for its own atomic weapons requirements. On the other hand, the Air Force could develop ‘a deceptive arithmetic’, computed from such data.

According to Morse, the ‘arithmetic’ of the Air Force planner worked as follows. First, a planner began his calculation about each target in the dim light of four important guesses: the estimate of the possible bombing error, the assumed probability of success in achieving a selected degree of damage to selected elements of the target. For example, if he assumed a 5 miles CEP (Circular Error Probable: the radius of the circle within which 50 per cent of the bombs dropped on a specific target may statistically be expected to fall) and a 50 per cent probability of achieving 50 per cent damage to a runway, the arithmetic gave him 20 MT as a necessary yield. If he raised the probability to 90 per cent with the same CEP, it meant 110 MT. ‘By such arithmetic, the Air planner can establish “requirements” for 60 MT, 120 MT as SAC now talks in briefings, or any other number without limit’. In short, as one pushed the assumed probability of success toward certainty, the required yield approached infinity.

The factors of degree of damage and elements of the target did not only affect the necessary yield, but also determined the height of the burst, ground or air. If the planner focused on the structural damage to facilities and demanded a high probability of destruction with a high CEP, the yield must be high, but also the weapons must be burst on or near the surface to maximize blast effects. A ground burst, however, inevitably generates a massive volume of induced radioactive fallout. If the ground burst was prohibited from the point of view of fallout, the yield had to be even higher to compensate for the decreasing blast effects by an air burst.

All the steps described above were applied to individual targets. Overall requirements were determined by simple addition, further modified to allow for operational losses and dispersion requirements. The military ‘requirements’, therefore, nearly automatically resulted in a tremendous number of very high-yield weapons, unless any other consideration, especially a political goal in a nuclear war, was allowed to interfere with this closed-circuit of ‘arithmetic’. Morse admitted that a financial factor played a certain role in the equation. But, at the military planner level, the controlling factors in reaching the weapons requirements were the ‘arithmetic’ and its arbitrary ‘assumptions’ based on uncertain information about weapons, the enemy, and themselves. Above all, the ‘over-riding urgency of preparation for the worst,’ or a scenario of massive nuclear exchange, dominated the planners’ thinking.

This mechanism for setting the military requirements, however, came under severe attack, as skepticism was rapidly growing about the validity of the ‘arithmetic’ and the Army began to contest the massive retaliation strategy. ‘Under existing differences of concept and competition for the stockpile’, Morse observed, ‘DOD approval of any guidance is difficult to obtain’. As he correctly predicted, the military alone could not settle these internal differences. At one point, the Joint Chiefs of Staff was tilted toward the cancellation of the clean TX-21 program, but confusion persisted about both Class A and B weapons requirements. In early April 1957 the military finally came up with a unified position about the requirements.

The military’s demand for the very large-yield clean bombs horrified many in Washington, especially foreign officers, who had been strongly concerned about the acceptance of US nuclear weapons policy by its allies since ‘Bravo’. By linking the development of clean weapons with the development of larger bombs, ‘the reassuring effect of the “clean” weapons development would be weakened’, the State Department argued. If the secret program of making a 60 MT weapon became public knowledge, it would undermine US standing in the current disarmament negotiations in London. It would also fuel public sentiment for a ban on nuclear testing and perhaps also a ban on nuclear weapons without regard to safeguards. And it would cause much trouble in obtaining allies’ consent for the introduction and use of US nuclear weapons. ‘The risk of such serious political disadvantages’, the State Department asserted, ‘must be set against whatever additional military strength the United States would gain’ from this 60 MT clean bomb project.

On 15 July 1957, before deciding upon the list of the objectives for Operation ‘Hardtack’, the 1958 nuclear testing series in the Pacific Ocean, Dulles and his advisers invited the military and AEC staff to settle their differences over the 60 MT question. They wondered why they had to conduct a test when no decision had yet been reached as to whether to stockpile these very large clean bombs. Such a development, they worried, might postpone the small clean bomb programs. And publicly, what the military proposed was directly against Eisenhower’s repeated assurances that his administration would not make a bigger bomb than it now possessed. Asked by Dulles if such a test was a matter of urgency, Strauss and Deputy Defense Secretary Donald A. Quarles suggested a single test, with a much lesser yield than an actual weapon, be included in Operation ‘Hardtack’ to establish the principle and technique of making a large clean bomb. On 26 July, Dulles, Strauss, and Wilson agreed on the position and the draft report was submitted to Eisenhower for approval. The President, however, was ‘very much in doubt’ about the necessity of testing and stockpiling such a big bomb. ‘Our statecraft was becoming too much a prisoner of our scientists’, he lamented. However, he eventually approved the recommendation. After all, what the President faced in the report was a logical extension of the massive retaliation doctrine he had embraced. His administration was becoming too much a prisoner of the passion of scientists for technological extremes, the inertia of the military’s ‘arithmetic’, and, above all, the inevitable consequence of his own strategy.

Away from mass destruction: Dulles, morse, and strategy for limited war

The question of a bigger clean bomb, however, was not the only case in which Eisenhower found himself ‘too much a prisoner of our scientists’. As the clean technology seemed feasible, some scientists attempted to push it toward another technological extreme—a smaller clean bomb for tactical purposes. This drive for new nuclear technology soon merged with a mounting call for a new nuclear strategy.

The origin of the idea of a small clean nuclear weapon can be traced back to the middle of 1954, when the upheaval triggered by ‘Bravo’ was still far from settled. Since then, the LASL had conducted a theoretical investigation into the feasibility of miniaturizing a clean bomb for tactical uses. The technological difficulty, however, seemed almost insurmountable. Precisely for this reason, clean technology had been applied to a high-yield nuclear weapon. This fact appeared to be well known even to the President. When he justified continued nuclear tests in terms of a clean weapon in his letter to Congressman W. Sterling Cole in May 1957, Eissenhower candidly admitted that, at the current technological level, the ‘cleanliness’ could by no means apply to weapons of small size and yield.

It was once again the UCRL, however, which put its stake on this technological extreme and offered an optimistic outlook on it. After Operation ‘Redwing’, the UCRL submitted to the AEC a projection for future clean weapons. In this estimate, York argued that a clean bomb at about 300lb and with a yield of around 10 KT might be feasible by the 1962–63 period. This device, however, involved new principles, which had not yet been subjected to any sort of test. As the fallout problem and the question of a test ban gained further impetus in 1957, however, the administration did not have the luxury of time to wait for an eventual success. Although Stevenson’s bid for the presidency failed and Eisenhower was reelected by a wide margin, the Democrats took on Stevenson’s claim about the danger of fallout and his call for a test ban. At the congressional hearings about fallout in 1957, many scientists challenged the AEC’s official position about the extent of the danger, stirring up confusion and controversy in public. By June, the AEC was determined to fight back, and started its search for any ‘new facts’ to be highlighted to shore up the government policy of continuing nuclear tests. Commissioner Libby had in mind ‘an extensive public education campaign’ in which he would take the leading role.

Such ‘new facts’ for public education were supplied by Edward Teller and Ernest O. Lawrence, the two most famous—and controversial—scientists at the UCRL and among the staunchest supporters of continued nuclear testing. Joined by Mark Mills, the head of the UCRL’s theoretical division, they threw sales pitches for the clean technology before the subcommittee of the Joint Committee on Atomic Energy on 20 June, and also before the full meeting next day. Their lobbying was highly successful. Arranged by Cole and accompanied by Strauss, the three scientists were eventually offered an opportunity to meet Eisenhower on 24 June and convince him of the importance of the clean technology.

Of course, it was not the first time the President heard anything about a clean bomb. What was new, however, was the scientists’ emphasis on two points. First, they informed Eisenhower that they would be able to make a small tactical clean bomb if they were allowed to research and test. Second, they implied to the President that the further development of the clean technology would open up a possibility of using a nuclear explosive for peaceful purposes like dynamite. Eisenhower seemed to be impressed by both points. Dulles also found this presentation wonderful. Soon he sent a cable to London where Stassen attended the United Nations Disarmament Commission subcommittee and checked his tendency toward a further compromise on a test ban issue by informing him that the President was thrilled by the importance of the clean technology, which required further nuclear tests. Congressman Cole turned into a zealous believer in the gospel of clean bombs and strongly endorsed the necessity of nuclear testing. ‘Atomic weapons need not be wanton, indiscriminate, or inhuman’, he claimed on the floor of the House. ‘They can be made precise and humane as any other weapon’.

The preliminary technical estimates on tactical clean weapons were laid out by York. He outlined three possible types for 20–200 KT clean weapons, based on a standard two-stage design (the yield from fission was expected to be 7–50 per cent of its total yield), a smaller fission primary design (2–15 per cent), and a new design (2–5 per cent). If one accepted many somehow unrealistic assumptions, the Type I might begin to enter the stockpile in 1960, the Type II in 1961, and the Type III in 1963. York admitted a substantial weight penalty, and calculated it as a factor of three to five compared to a pure-fission bomb of the same yield. Operationally, however, it might not be a big problem. After all, as York pointed out, the significance of a clean tactical weapon rested with its political and military implications. The recent Army ‘Sagebrush’ exercise, which involved simulated ground bursts of standard tactical weapons on airfields, vividly illustrated that such applications were very dangerous due to their inevitable heavy radioactive contamination. Probably, it might be generally impossible for the US to count on the current types of atomic weapons for tactical uses. Some operational deficiencies of a clean tactical weapon could be to some extent tolerated, if it was compared to the urgency of its application to nuclear strategy.

Indeed, York’s argument about the importance of a tactical clean weapon matched the growing interest of many politicians and military officers in a strategy for limited nuclear war as an alternative to that of massive retaliation. Among them was, perhaps unexpectedly, Secretary Dulles, whose name was in public firmly associated with massive retaliation. Since ‘Bravo’, he had embarked upon his soul-searching journey to find an alternative to his strategy. First, ‘Bravo’ taught him that US allies simply could not accept his tough strategy. ‘Bravo’ seemingly illustrated a scenario of wholesale destruction ensued by massive use of nuclear weapons. This arose a tremendous psychological and political pressure among US allies to stay out of a nuclear war—and, if possible at all, the Cold War too—and thus endangered the solidarity of the Western alliance. Second, the strategy might fail to make nuclear weapons as a credible deterrent. Dulles was convinced that nuclear deterrence would work ‘only if the weapon is used or if people think it will be used’. Now that people gradually learned the real implications of massive retaliation, such a use of nuclear weapons seemed quite unbelievable.

Furthermore, as the nuclear arms race intensified, the superpowers’ strategic nuclear arsenals would reach a point of saturation, creating a nuclear stalemate. Such a situation would create mutual deterrence, which might, in turn, tempt the Soviet Union to engage in a limited war without fear of US strategic retaliation. After all, many people argued, the US would not sacrifice New York to save Berlin or Paris. This strategic prospect was driven home to European allies when the Soviet Union launched Sputnik I in October 1957, which suggested a Soviet capacity to attack the US directly with ICBMs. Now ‘a naked promise of nuclear protection by another is no longer a sound basis for any major country’s security’, the State Department admitted in the aftermath of the Sputnik shock. ‘Our NATO friends need further earnest of our firm intention and resolution to bring nuclear force into play if deterrents fail to keep the peace.’ Dulles felt even more pressed than before to demonstrate that the US would be ready to fight a nuclear war to protect its foreign allies, without destroying itself and them. Massive retaliation now seemed a braggadocio, not a reasonable strategy to deter the Russians and maintain the cohesion of the Western alliance.

In his search for a post-massive-retaliation strategy, Dulles tried first to count on tactical weapons. The advance of nuclear technology now seemed to make a nuclear weapon smaller in size and yield, usable for limited purposes in warfare rather than only for mass destruction. ‘The United States has not been content to rely upon a peace which could be preserved only by a capacity to destroy vast segments of the human race’, he argued in a Foreign Affairs article in October 1957. ‘It seems now that their use need not involve vast destruction and widespread harm to humanity. Recent tests point to the possibility of possessing nuclear weapons the destructiveness and radiation effects of which can be confined substantially to predetermined targets’. In essence, he would not acknowledge any fundamental difference between nuclear weapons and conventional weapons. He simply believed that a nuclear weapon was a higher form of a conventional weapon, and at least its use in a limited way could be justifiable. Therefore, Dulles found no reason why he should think that any use of small nuclear weapons in a local war would automatically trigger escalation to an all-out nuclear war and a nuclear holocaust. But a main question surrounding the escalation problem is how to ‘cooperate’ with your enemy to limit escalation by signaling your limited goals and means while checking the enemy’s desire to escalate in its favor. As Bernard Brodie, a prominent American nuclear strategist, pointed out, the use of any kind of nuclear weapons might send a clear signal of escalation, not of limitation, to the enemy and thus increased the chance of deadly spiral escalation. Sir Lawrence Freedman, a British nuclear strategist and historian, has aptly captured the psychology behind advocates of use of tactical nuclear weapons: ‘By using the adjective ‘tactical’, it was hoped to link nuclear weapons to weapons of the past and to traditional land warfare.’ By the end of the 1950s, however, ‘it was apparent that this link was illusory. Nuclear weapons, whatever their shape, size or ostensible purpose, could not be considered “just another weapon’”.

In retrospect, it might be true. Amazed by the fast-evolving nuclear technology, however, many politicians and military planners of the time were eager to try a technological solution to nuclear strategy. Captain Morse’s lobbying for a small clean weapon and its role in the limited warfare strategy is an interesting illustration about how nuclear strategy and nuclear technology shaped each other.

As has been discussed, Morse had bitterly criticized the ‘arithmetic’ mechanism of the military requirements for overkill. Even before the Sputnik shock belatedly awakened Americans from an illusion of massive retaliation, the Captain had patiently pointed out that the massive US strategic nuclear forces could not deter or fight local aggression. In August 1957, Evan Aurand, Eisenhower’s naval aide, endorsed Morse’s argument, observing that ‘the US has already proved Captain Morse’s thesis by not using its deterrent power in connection with Korea, Indo China and other situations’. In early 1958, as the Sputnik shock foreshadowed the age of strategic mutual deference, Morse was more convinced about the bankruptcy of the old nuclear strategy. ‘The Soviet Union had just about completely maneuvered us into the position where we could no longer rely on the concept of massive retaliation’, he observed. The Russians would take the attitude that ‘in effect our nuclear capability was practically neutralized’, which would embolden them to deploy their conventional forces without much fear of nuclear retaliation. Therefore, he concluded, ‘we must be in a position to counter conventional attacks with small tactical weapons with yields of about 1 KT or less’. According to him, ‘we clearly could not use existing “dirty” weapons in tactical situations because of the political liabilities involved’. Furthermore, he thought that using current tactical weapons ‘would practically amount to strategic use because of the carryover of damaging effects to nearby cities or populated areas by fallout’. He wondered how long neutrals or friends in areas of limited war would remain neutrals or friends after suffering heavy casualties from the indiscriminate use of US nuclear weapons. The development of a small clean weapon would thus be ‘essential to provide us with a politically usable tactical weapon’. In his mind, a small clean weapon would be a powerful tool to remove the taboo against a nuclear use. It would also send a clear signal of limitation to the enemy, reduce the risk of escalation, and thus keep nuclear warfare limited. The clean technology was desirable also for an anti-missile nuclear missile, which should be usable over the friendly territory without worrying about fallout.

As Morse was even more conscious than before about the politico-military importance of the clean technology in the limited warfare strategy, he was also much alarmed by mushrooming world opposition to continued nuclear tests, which were indispensable for the advance of nuclear technology. Although he admitted that a small clean weapon could be developed by underground testing, he was afraid of the public pressure which demanded a total cessation of nuclear tests, both atmospheric and underground. The President had already admitted that testing was bad, and the main US opposition to a test ban was derived from the problem of an effective inspection rather than from military problems. Morse therefore doubted that they could suddenly change their stand and say ‘testing is now good and we plan to do it’.

Morse’s doubt, however, did not prevent him from trying to sell this new rationale—a small clean weapon—for continued nuclear tests. In late January 1958, he approached F. M. Dearborn, special assistant to the President who had been deeply disturbed about the declining US capability for limited war. Soon, they successfully recruited Robert Cutler into their circle to ask the President to ‘drastically revise both weapon and public information policies from the top down, against strong internal opposition’. A major critic of the massive retaliation strategy, Cutler was expected to approach the President in his capacity as national security adviser. A memorandum for Eisenhower was drafted and revised several times. In it, Morse and others called for a presidential announcement before the UN or other forum of the following four actions: (1) to produce and use only clean weapons, and use them only in self-defense; (2) to eliminate all or most of the danger from nuclear testing by testing underground or by testing aboveground in clean versions only; (3) to propose an immediate international study of rules to limit nuclear warfare in terms of objectives, targets, weapons and areas; and (4) to share the principles of clean weapons with the Soviet Union in hope that it might protect the rest of mankind in the event of nuclear war.

On 16 March 1958 Cutler wrote two memoranda, both of which were inspired by the almost certain prospect of the nuclear stalemate and the almost incalculable scenario of a massive nuclear exchange. In his memorandum titled ‘Massive Exchange of Nuclear Weapons’, he referred to a recent study which exposed an awful result of the ‘military requirements’ mechanism for nuclear weapons, which had been discussed by Morse as the ‘arithmetic’ problem. Pursuing the certainty of the total destruction of numerous military targets, the military tended to demand more and more nuclear weapons. As a result, a preliminary exchange of nuclear weapons within the first 15 hours of war would amount to 7,000 MT in yield, roughly 350,000 times as great in magnitude as the nuclear explosion at Hiroshima. The effect of such an instant and massive exchange was beyond any comprehension. Therefore, Cutler called attention to ‘a need for strict civilian control over the objectives upon which “military requirements” for nuclear weapons and forces are based’. He also urged active intervention of ‘other than purely military considerations [italic original]’ into the plan of producing and using nuclear weapons. In short, he demanded a total departure from the concept of massive retaliation as a strategy.

It is well known that a National Strategic Target List (NSTL) and a Single Integrated Operational Plan (SIOP) would later attempt to address Cutler’s concern of overkill by trimming out the list of means and targets. As it was believed that the Western alliance could not match the Communist camp with conventional armament and manpower, the last alternative seemed to be possible, or even desirable, if the US had tactical clean nuclear weapons in its inventory. Therefore, Cutler argued, it was very important that ‘the U.S. continue to retain its right to test nuclear weapons…. until it has solved the secret of how to make small “clean” weapons’. In his mind, a small clean bomb was a key to lay a technological basis for his limited warfare strategy to replace the strategy of massive retaliation. It was also a major challenge to the mass destruction that would inevitably result from the use of non-discriminatory high-yield nuclear weapons. Such a bomb, Cutler and others hoped, would make a nuclear war a reasonable option again, and rescue the US from the dilemma of massive retaliation in the nuclear stalemate.

President Eisenhower, however, did not agree with Cutler. As Campbell Craig has shown in his study, Eisenhower consistently rejected an alternative to the massive retaliation strategy, an attitude in clear contrast to a growing doubt shared by Dulles, Cutler, and others inside and outside the administration. Unless he was willing to consider any option other than a sheer nuclear annihilation, there was no utility in clean weapons. Indeed, after discussing Cutler’s memorandum, Eisenhower and others concluded that ‘We would not use clean weapons in connection with massive retaliation.’ They simply reiterated a position that the US ‘will use its nuclear retaliation if Europe attacked [italic as original]’, as if it were a matter of faith, despite the eroding credibility of the proclamation in the European eyes. Informed of the conclusion, Morse was ‘discouraged but not deterred by the President’s failure to grasp the importance of clean weapons’. The ideas Cutler had presented to Eisenhower, in his opinion, were ‘simply too advanced for his absorption at present [italic as original]’. Morse had an unshakable belief that small clean weapons, making limited nuclear warfare feasible and rational, would lead to peace in the age of mutual deterrence. In July 1958, he was still ‘thoroughly convinced that the clean weapons concept is sound and will be recognized as such in time’. He was a true believer in a clean weapon. For him, it was a savior of peace, not a political gimmick.

Morse was, however, not the only believer. Secretary Dulles still embraced the gospel of a clean bomb, which seemed to solve the dilemma of massive retaliation and restore support from US allies. In May 1958, when he met a group of US ambassadors in Europe, the Secretary vehemently justified the importance of a clean bomb, or a ‘limited bomb’, in the European context:

We seek a limited bomb which would be acceptable for defense purposes on the Continent of Europe without great risk, without destroying all the lives of the people we want to save. If you are going to have war and use these things in Europe you do not want to kill all the Europeans or the Hungarians and the Poles. Or, if the wind shifted, you would risk killing the British or the French or the Dutch.

In the approaching nuclear stalemate, Dulles and his advisers knew the necessity of presenting ‘evidence’ for the Europeans to believe that nuclear warfare could be conducted with some discrimination. They suspected that there was a growing feeling in Europe that the ‘measurable’ political death and loss of freedom might be preferable to the ‘immeasurable’ destruction and slaughter of nuclear war. Therefore, they hoped that the availability of clean weapons for European defense would infuse the Europeans with an idea that ‘initiating nuclear warfare in Europe would be either a rational act or one over which the Europeans would have any [sense of] control’.

On 7 April 1958 Dulles reviewed the problem of massive retaliation thoroughly with his colleagues. He recalled that he had originated the concept of massive retaliation in 1950 when the Korean War convinced him that it was impossible for the Free World to match the conventional strength of the Soviet Union in each local point of conflict. At that time, he explained, the development of nuclear weapons had not reached a point which would permit the US to consider an ‘area defense’ concept. Since 1950, however, the destructive power of nuclear weapons had immensely increased to the extent that massive use of nuclear weapons could not guarantee the very survival of the US itself. He wondered if the doctrine of massive retaliation reproduced itself by developing nuclear weapons suitable for no less than massive retaliation. ‘Are we’, asked Dulles, ‘becoming prisoners of our strategic concept and caught in a vicious circle?’ In an attempt to escape from such a pitfall, he pointed out a new direction of nuclear technology. ‘As tactical and clean nuclear weapons become available’, he said, ‘our present strategic concept may not continue to be the only practical one’. Defense Secretary Neil H. McElroy seconded his argument, calling for a new doctrine which would govern use of tactical clean weapons in limited war without an unacceptable risk of escalation. Dulles echoed: ‘Are we not wasting money testing to develop “clean” and small nuclear and atomic weapons if we have no strategy for their use?’

At this critical moment for nuclear strategy and technology, however, a nuclear test ban issue flared up as the Soviet Union won a propaganda victory at the end of March 1958 by announcing its unilateral intention to suspend all nuclear tests. In the magnitude of its effect on US foreign relations, this statement was equally as devastating as ‘Bravo’. Once again the US seemed militaristic and amoral, and its allies and world opinion doubted US global leadership in the Cold War. Dulles contradicted himself when he pressed for a test ban and called for a larger role for small clean nuclear weapons in nuclear strategy. It might be possible that Dulles forgot the fact that the clean technology for small weapons was far from complete. Indeed, a UCRL’s ‘small’ clean device tested on 2 July, ‘Shot Cedar’, yielded as much as 220 KT. This failure, according to Hans A. Bethe, a prominent scientist and member of the President’s Scientific Advisory Committee, stemmed from an ambitious drive for cleanness to an unnecessary and unpractical extent.

For Teller and other scientists, however, the setback underscored the absolute need of another test. On 12 August 1958 Teller met Eisenhower and told him that such a device was useful not simply for military purposes but also for peaceful purposes. This last-ditch appeal, however, did not work. ‘The new thermonuclear weapons are tremendously powerful’, the President said. ‘However, they are not, in many ways, as powerful as is world opinion today in obliging the United States to follow certain lines of policy.’

Eisenhower’s keen political acumen, however, does not fully explain the administration’s low regard for clean weapons. By late May, a study on the projected US capabilities in limited warfare through July 1961, which Dulles had advocated and awaited, finally came out, but failed to find any legitimate place for small clean weapons in it. ‘Even if a breakthrough is made and it is followed by a very high priority production program’, the study soberly stated, ‘there is only a remote possibility that “clean” nuclear weapons in the lower yield categories will be available to US military forces within the time frame of this study.’ The failure to incorporate small clean weapons into a new nuclear doctrine, together with their technological difficulty, might have poured cold water on Dulles’ enthusiasm for clean weapons by the summer, a decisive moment to choose if the US discontinued nuclear tests.

On 22 August 1958, with Dulles’ support, Eisenhower went to public and announced that the US would suspend all nuclear tests for one year from 31 October, 1958. He not only shut down nuclear testing, but also closed off the possibility of accelerating the development of small clean weapons. What he could not close off, however, was the ever-heated controversy over an alternative strategy to the doctrine of massive retaliation. With the path to a reliable technological innovation no longer available at least for the time being, the debate over an alternative strategy lingered beyond the term of the Eisenhower administration.

Conclusion

The search for clean bombs served to perpetuate the momentum of US nuclear testing even after the fiasco of ‘Bravo’. Behind the search lay scientists’ undaunted drive toward technological extremes. The military, for its part, added some thrust with its own inertia of using ‘arithmetic’ in planning a nuclear war and calculating the required number of nuclear weapons. The heated debate over big and small clean weapons within the Eisenhower administration also reflected and enhanced the drift of nuclear strategy away from massive retaliation. Dulles and Morse came to believe that they had finally found in small clean weapons a magical answer to the riddle of nuclear strategy in the hydrogen bomb era—how to restore Western political solidarity, retain an effective deterrent to war of any kind, and reclaim the traditional meaning of ‘political goals’ and ‘military victories’ in nuclear warfare. As the advance in technology had made the nuclear genie too big and ubiquitous to be put back in the bottle, the trajectory of the Eisenhower administration’s exploration for a ‘usable’ nuclear weapon with a ‘reasonable’ nuclear war plan, illustrated by the clean bomb episode, indicates the ever-narrower middle ground in which the administration had to steer itself between a vision of nuclear peace and that of nuclear destruction.