How Hans Bethe and Richard Garwin served the missile defense system they publicly criticized

Editor’s note: This article has been changed since its original publication. See “Post-publication changes” below for details. Critical responses to the article can be found here, here, here and here.

In September 1967, Defense Secretary Robert McNamara announced that the United States would deploy an antiballistic missile (ABM) system of radars and nuclear-tipped interceptors capable of defending the country against ballistic missile attack. The Pentagon soon named^[a] the deployment “Sentinel” (not to be confused with today’s program of land-based intercontinental ballistic missiles). The system was not designed to defend against an all-out strike by the Soviet Union, McNamara explained. Instead, Sentinel would provide a “light” defense of the continental United States against missile threats from China and accidental launches of any origin.^[1]

The following March, physicists Hans Bethe and Richard Garwin published an article in the magazine Scientific American that sharply opposed the Sentinel deployment. Bethe and Garwin argued that Sentinel could be overwhelmed by a missile barrage and confused by countermeasures such as decoys and radar-blinding high-altitude nuclear detonations—by the Soviet Union, and by China too. An attacker could more cheaply add missiles and countermeasures than a defender could counteract them. The two scientists explained that they had used “nonsecret information” about the system, along with back-of-the-envelope physics calculations, to prove their point.^[2]

With their article, Bethe and Garwin became a public face^[b] of scientific opposition to missile defense during the Cold War. Bethe was one of the 20th century’s greatest physicists; Garwin had been deemed a “genius” by his mentor Enrico Fermi. Two illustrious thinkers, it seemed, were speaking truth to power. By challenging the Sentinel system, Bethe and Garwin had challenged the military-industrial complex and upheld the independence of science—or so it appeared to the public.

Yet^[c] Bethe and Garwin did not oppose missile defense per se, and they were not entirely independent scientists.

As corporate consultants, they helped create the technologies that made the Sentinel ABM system possible. As government advisors, they helped devise the arguments McNamara would later use to rationalize the system’s deployment. Bethe and Garwin were not opposed to the military-industrial complex; they were deeply embedded in it.

How, then, did Bethe and Garwin come to publish an article openly criticizing a defensive system resembling one they had supported for years? In short, they were drawn into a new kind of public performance by outsiders who desired displays of oppositional politics by scientists. And Bethe and Garwin obliged.

Defenders of missile defense. Bethe had learned most of what he knew about missile defense as a paid consultant to the Avco Corporation, a top designer of intercontinental ballistic missile (ICBM) reentry vehicles for the US Air Force. He did important work for the company, helping design stealthy reentry vehicles and decoys that were less visible to radar and modeling the effects of X-rays (like those created by a nuclear explosion) on reentry vehicles.

Bethe also helped Avco with its work on missile defense. His calculations considered whether decoys and reentry vehicles could be distinguished based on the wakes they created as they streaked through the atmosphere. Avco provided the reentry vehicles for a series of high-altitude nuclear tests in 1962, leading Bethe into a years-long classified debate with fellow weapon scientists about the complex physics of radar blackout. (It was that knowledge—not back-of-the-envelope physics calculations—that later informed the relevant passages of his article with Garwin.)

As a government advisor, Bethe helped Avco win major contracts, primarily as a member of the White House’s President’s Science Advisory Committee (PSAC). On the committee, he and his colleagues presented not only technical details but also strategic arguments that prepared the way for what later became the Sentinel system.

Consider one PSAC study from October 1960: The committee’s advisors argued that although it would be unwise to deploy a heavy system defending against “a determined Soviet effort,” there were “valid arguments for a more limited deployment.” A light deployment could strengthen deterrence by “increas[ing] the uncertainty in the minds of the Soviets as to the effectiveness of their missiles,” making “less likely a Soviet decision to attack.” In addition, a light system would protect the United States against accidental missile launches and weaker strikes by “powers other than the Soviet Union.” Out of four possible budgets for missile defense being considered by the Eisenhower administration that year, Bethe argued that the highest ($335 million, or roughly $3.7 billion in 2025) was necessary.^[3]

By 1965, the Army and its ABM development contractor, Bell Laboratories, were proposing that the United States move forward with a “limited deployment” defending against lighter attacks involving fewer missiles and “unsophisticated” attacks lacking offensive countermeasures. Such attacks would likely come from China, which had tested its first nuclear device in 1964. The new strategic military panel of the President’s Science Advisory Committee, on which Bethe and Garwin both served, reviewed the Army-Bell proposal and concluded that the deployment would indeed be “very effective” against China. The system would have “considerable capability” against the Soviets, too, although it might push the Soviets “to higher strategic force levels.” The committee recommended against deployment but urged the Pentagon to “design and evaluate a simplified area defense system” using “off-the-shelf” radars and interceptors, and to continue research and development “in support of the proposed Army-[Bell] program.”^[4]

As rumors of deployment began to build during 1967, Bethe supported the Pentagon’s plans. During a talk at the University of Wisconsin-Madison in March, he explained that intercepting a small number of missiles above the atmosphere (a requirement for area defense) was straightforward. Bethe recalled Nikita Khrushchev’s 1962 remark that a Soviet missile defense system was capable of “hitting a fly in space.” The comment had been ridiculed at the time by Western commentators. Not by Bethe: “Figuratively I think this is quite well stated, you can really do that,” he said during his talk. Bethe explained that he was against a heavy ABM system deployment, but when asked about a lighter deployment, he admitted that “this is a very valid argument.” Against a lesser missile force, “a defense might actually be quite useful.”^[5]

In notes written in August that year, Bethe explained that a “possible use of ABM which might stabilize the military situation is a light deployment of ABM against ‘nuisance attacks’ from medium-sized powers, such as the Chinese might become in the mid-1970s.” China, according to Bethe, “will not have the industrial capacity or the money to deploy any large number” of missiles, nor the resources to make “sophisticated” countermeasures. Alert to the possibility that missile defense could be banned under a strategic arms limitation agreement, Bethe insisted that light area defense and “ABM defending missile silos [should] be permitted” under any treaty prohibiting a heavy area defense.^[6]

After McNamara’s announcement, Bethe continued his support for missile defense.

Defending against China “is not complete nonsense,” he told an audience at Cornell University in October 1967. “The people who advocate this and make the decisions are not fools.” China would have trouble developing “sophisticated decoy systems because they cost a lot of research and development.” A light area defense that intercepted reentry vehicles at high altitude would provide insurance against an accidental missile launch. “Terminal defense” of ICBM silos, which required intercepting missiles lower in the atmosphere, was “a feasible and fairly easy job.”^[7]

Richard Garwin, like Bethe, had also consulted for the Avco Corporation and another defense contractor,^[d]
and he too supported a light area defense. “I do think that there are some uses for a light ABM,” Garwin noted in a letter in early 1968, but he wanted a different configuration of radars and interceptors. Garwin believed there should be “one PAR [radar] in the Washington-New York area, and another perhaps on the West Coast and perhaps a third in the Chicago-Detroit area, together with a few dozen Spartan [interceptor] missiles to handle just a few Chinese missiles.”^[8]

Strategic opposition. Then, an accident of circumstance led Bethe and Garwin to publish their famous article.

In December 1967, the two physicists participated in a panel on ABM sponsored by the American Association for the Advancement of Science. The event was attended by Gerard Piel, publisher of Scientific American, who personally opposed the Sentinel deployment. After hearing the talks, Piel became convinced that because Bethe and Garwin were uncomfortable with a heavy area deployment, they opposed missile defense in general. He asked the physicists to write a joint article for the magazine, and they agreed. The drafts they turned in, however, alarmed Piel and his fellow editor Dennis Flanagan. “At the very least,” Flanagan wrote to the authors, “the educated layman … may very well come away from the article feeling that both of you are generally in favor of missile defense”—as they in fact were.^[9]

What took place next was a kind of assertive handholding. An editor (likely Flanagan) rewrote the article’s introductory section and other key passages. According to the published version, “the ‘light’ system described by Secretary McNamara will add little, if anything, to the influences that should restrain China indefinitely from an attack on the United States.” It was “well within China’s capabilities to do a good job” at designing countermeasures against Sentinel. The program would “nourish the illusion that an effective defense against ballistic missiles is possible.” Although their critique focused on area defense, the authors added that they did “not mean to suggest that a terminal-defense system^[d]
can be effective.”^[10]

Each of these points reversed arguments Bethe^[e] had made for years, and in the weeks preceding the article, both in classified settings and in front of various audiences. It’s hard to say why the two physicists agreed to the changes, but there can be little doubt they understood that their editors expected a different statement than the one they initially planned to offer.

Crucially, Bethe and Garwin seem to have calculated that they could become public “opponents” of the Pentagon without abandoning their status as insiders or their private work on behalf of the administration’s policy.

At an event in Cambridge, Massachusetts in early 1969, Bethe declared: “I believe that most of the audience here is against the ABM, and I believe that I am here to tell you why.” Days later, President Richard Nixon announced that his administration was amending the deployment under a new name: “Safeguard.” The new deployment would focus on defending ICBM silos—another mission Bethe had long judged to be strategically and technically sound.

In public, Bethe said he remained opposed to the deployment. Privately, he reassured the chair of the President’s Science Advisory Committee, Lee DuBridge, that he was “of course willing to continue to work toward making the [Safeguard] system, as now approved, more effective.” Garwin likewise declared that he was opposed to Safeguard—not because silo defense was unwise, but because improved interceptors and radars could accomplish the job better.^[11]

The United States and the Soviet Union later signed the 1972 ABM Treaty banning the deployment of national missile defense systems. This result, widely hailed as a landmark achievement of Cold War arms control, had not come about because scientists had proven that missile defense was faulty and dangerous, nor because they had spoken scientific truth to political power. Indeed, if the most famous scientific “opponents” of ABM had gotten their way in the late 1960s, the United States would have deployed a national ballistic missile defense system.

The revised story of Bethe and Garwin offers a cautionary lesson. Nuclear thinkers and historians should avoid the complacent thought that rational expertise can transcend politics in the field of strategic weapons. As the story of Bethe and Garwin shows, strategic and technical arguments can be remarkably malleable—even in the hands of figures we might assume wield the arguments with the greatest integrity and on strong scientific grounds. Such arguments can be shaped by commitments and interests that are not readily apparent in public discussions.

Ultimately, no insider expert—no matter how brilliant, prestigious, and well-intentioned—can rise above the system they operate in. The commitments and interests of that system and its insiders deserve scrutiny and political engagement. The system itself should be up for debate.

Post-publication changes

[a] The original word, “nicknamed,” was changed to “named”.
[b] The original usage, “the public face” was changed to “a public face”.
[c] The original phrase “for all their posturing” was deleted.
[d] Originally, the sentence said “other defense contractors” but has been changed to “another defense contractor,” for accuracy. The Bulletin regrets the error.
[d] The original sentence included a parenthetical explanation that incorrectly suggested that the system related to silo defense. The Bulletin regrets the error.
[e] The original incorrectly included the words “and Garwin” at this point in the sentence. The Bulletin regrets the error.

Notes

[1] “Remarks by Secretary of Defense Robert S. McNamara, September 18, 1967,” Bulletin of the Atomic Scientists 23, no. 10 (1967): 26–31, on 31.

[2] Richard L. Garwin and Hans A. Bethe, “Anti-Ballistic-Missile Systems,” Scientific American 218, no. 3 (1968): 21–31.

[3] “Memorandum for the Record, Subject: Nike-Zeus,” October 18, 1960; Bethe to Rathjens, October 26, 1960, Box 4, Folder “AICBM [June–December 1960] (3),” Office of the Special Assistant for Science and Technology Records, 1957–61, Dwight D. Eisenhower Library.

[4] “Report on the Proposed Army-BTL Ballistic Missile Defense System by the Strategic Military Panel of the President’s Science Advisory Committee,” October 29, 1965, doc. NH01411, Digital National Security Archive.

[5] “Draft of talk given by Dr. Hans A. Bethe at the University of Wisconsin, Madison, Wisconsin, March 3 [or] 4, 1967,” Box 65, Folder 24, Hans Bethe Papers, Cornell University Division of Rare and Manuscript Collections.

[6] “ABM paper written Aug. 67,” Box 65, Folder 28, Hans Bethe Papers, Cornell University Division of Rare and Manuscript Collections.

[7] “ABM Cornell Talk 2 X 67,” Box 28, Folder 44, Hans Bethe Papers, Cornell University Division of Rare and Manuscript Collections.

[8] Garwin to Flanagan, January 3, 1968, Box 68, Folder 23, Hans Bethe Papers, Cornell University Division of Rare and Manuscript Collections.

[9] Flanagan to Garwin and Bethe, January 12, 1968, Box 68, Folder 23, Hans Bethe Papers, Cornell University Division of Rare and Manuscript Collections.

[10] Garwin and Bethe, “Anti-Ballistic Missile,” on 21, 25, 31.

[11] Bethe to DuBridge, March 21, 1969, Box 80, Folder 7, Hans Bethe Papers, Cornell University Division of Rare and Manuscript Collections; Richard L. Garwin, “This is a copy of a letter I sent to each Senator,” July 10, 1969, Box 8, Folder 3, Murray Gell-Mann Papers, Caltech Archives and Special Collections.