U.S. Presidents and the Nuclear Taboo

Having presided over the atomic bombings of Hiroshima and Nagasaki, President Harry S. Truman did not want atomic bombs used again if he could help it.  The recently created Atomic Energy Commission had custody of the weapons and Truman wanted them kept under civilian control for the time being. The armed services sought direct control of atomic weapons and as Cold War tensions heightened during the Soviet blockade of West Berlin, senior defense officials urged Truman to transfer custody from the AEC.

Advised to give the Pentagon leadership a chance to make its case, on 21 July 1948, Truman met with Secretary of Defense James V. Forrestal, Secretary of the Air Force Stuart Symington, and Secretary of the Army Kenneth Royall, along with Atomic Energy Commission Chairman David Lilienthal and the other members of the Commission, including Lewis Strauss.  Also present was Donald F. C Carpenter, the chairman of the Military Liaison Committee to the Atomic Energy Commission, who to Lilienthal’s dismay and Truman’s displeasure, read aloud the defense proposals, until Truman cut him off saying “I can read.”

Forrestal’s diary entry conveyed the crux of the meeting, but Lilienthal’s account was fuller, including Truman’s widely quoted statement about why atomic bombs could not be used like other weapons.  Lilienthal recounted Truman saying, with a “poker face”: “You have got to understand that this isn't a military weapon … It is used to wipe out women and children and unarmed people, and not for military uses. So we have got to treat this differently from rifles and cannon and ordinary things like that."   

Forrestal and Symington pressed their case but Truman would not relent.  According to Forrestal’s account, Lilienthal supported Truman by arguing that the “atomic bomb was not simply another weapon but an instrument of destruction which carried the widest kind of international and diplomatic implications.”  Three days later, Truman publicly announced his decision to retain civilian custody of the weapons. Over time, Truman would relax his position on custody, but not his basic thinking on nuclear weapons use.

Atomic Energy Commission Chairman David Lilienthal's detailed account of the discussion of custody issues with President Truman.

That top officials in the recently elected Eisenhower administration recognized the existence of a taboo against the use of nuclear weapons, and rejected it, is evident in the record of a meeting between Secretary of State John Foster Dulles and British Foreign Secretary Anthony Eden. The latter sought renewal of an understanding reached with President Truman that the United States would consult with the United Kingdom if the U.S. used its British air bases to launch nuclear strikes and would also consult, if time and circumstances permitted, with London if it was going to use nuclear weapons anywhere.

During a discussion of the consultative arrangements with Anthony Eden, John Foster Dulles said that he disliked them because the understanding singled out nuclear weapons as especially pernicious. Objecting to a "taboo ... on inventiveness," Dulles believed that it was "wrong to attach the stigma of immorality to any particular weapon," thus rejecting Truman's tacit prohibition of nuclear use. Dulles argued that "the first wild animal that was killed by man armed with whatever weapon, be it club or stone, felt that man had taken unfair advantage of it." Nevertheless, Dulles agreed to continue the understanding on consultations, although he and Eisenhower rejected the idea of making a personal presidential commitment.

During a review of national security policy, President Eisenhower spoke of using atomic bombs to end the Korean War (see page 9) but also observed (page 13) that doing so would scare allies who feared that they would end up in a "battleground" between the superpowers. Nevertheless, Eisenhower and Secretary of State Dulles worried about a nuclear taboo that constrained the use of nuclear weapons. They "were in complete agreement that somehow or other the tabu which surrounds the use of atomic weapons would have to be destroyed." Dulles explained the problem further: "in the present state of world opinion we could not use an A-bomb, [therefore,] we should make every effort now to dissipate this feeling, especially since we are spending such vast sums on the production of weapons we cannot use."[9]

Five years later, with the Soviet Union's ICBM program raising concern among the U.S.'s European allies that U.S. vulnerability to Soviet attack would reduce the value of its security guarantees Secretary of State Dulles met with top advisers to discuss whether the massive retaliation "strategic concept is retaining the confidence of our allies and continuing to create sufficient fear in the enemy to deter aggression." The discussion did not provide straightforward answers and the participants saw no clear way to use the new varieties of tactical and "clean" nuclear weapons that were being developed.

Dulles did not mention wanting to destroy the nuclear taboo as he had in 1953 and it was evident that he acknowledged the differences between using conventional and nuclear weapons. Speaking of the "awesome decision that faced President Truman in 1945," Dulles argued that "the situation today would be immensely more difficult." The President might believe that he would use nuclear weapons in a particular contingency but "that is one thing; what he actually would do when faced with an ambiguous Soviet attack or probing operation in Europe is another." In his judgment, the President would not direct a nuclear attack on the Soviet Union if a Soviet action against Western Europe was "not a clear-cut, all-out attack."

This report from Foreign Secretary Selwyn Lloyd suggested that Eisenhower had begun to accept ideas that nuclear weapons were not like other munitions and could not be used first. Lloyd reviewed his discussion of the Taiwan Strait situation with Eisenhower at the summer White House in Newport, Rhode Island. Chinese forces had been bombarding the offshore islands since August and the British had worried that the United States would use nuclear weapons to destroy the batteries. Having already decided that if conflict emerged he would order the use of conventional weapons first, Eisenhower told Lloyd that "it was out of the question to use nuclear weapons for a purely local tactical counter-battery task. If nuclear weapons were to be used it should be for the 'big thing,'" by which he meant general nuclear war. Quoting Eisenhower, Lloyd wrote: "He said 'when you use nuclear weapons you cross a completely different line.'" Implicitly, Eisenhower was acknowledging a significant difference between conventional and nuclear weapons. That, he said, was "his personal view and not necessarily the advice he would get from the Joint Chiefs of Staff."

During a lengthy meeting on proposed language on limited war in the administration's boiler-plate national security policy document, Eisenhower made several statements about nuclear weapons use, but nothing as forthright as "crossing a completely different line," perhaps because one of the meeting attendees was former JCS Chairman Admiral Arthur Radford. The Admiral spoke approvingly of the 1953 "New Look" policy to "convert our present forces to nuclear weapons capability," which enabled smaller units to "do a job which otherwise could only be done with much larger forces." Eisenhower did not dispute that, but when Secretary of Defense McElroy mentioned that some military commanders "feared that nuclear weapons would not be used," Eisenhower was not sympathetic. He "gave an analogy of the use of a pistol in retaliation for an attack by a hoodlum in the street. One is justified in using the pistol if one's life is really endangered, but not if the circumstances indicate that no such danger exists." The implication was that nuclear weapons, because of their disproportionate effects, should be used only when the nation's existence was at risk. To that extent, Eisenhower was treating nuclear weapons use as crossing a line.

Yet he reverted to earlier skepticism about the nuclear taboo. When Secretary of State Herter mentioned "how fearful world opinion was of any use of nuclear weapons." Eisenhower replied that "world opinion was wrong." Yet, having failed to convince world opinion to consider nuclear weapons as more powerful conventional munitions, o during his administration, Eisenhower was constrained and influenced by the nuclear taboo.

Several statements that John F. Kennedy made during the fall of 1962 conveyed nuclear taboo thinking. On 29 October 1962, Kennedy met with the Joint Chiefs for discussions of the Cuban situation. One of them, Marine Corps Commandant General David Shoup raised the prospect of tactical nuclear weapons use, if somehow the Cubans got control of the weapons that the Soviets had deployed to the island. Shoup saw a nuclear war starting if tactical nuclear weapons were used and Kennedy agreed that "in extremis" everybody would use them. What particularly worried him was that "the decision to use any kind of a nuclear weapon, even the tactical ones, presents such a risk of it getting out of control so quickly...." Shoup interrupted him and Kennedy did not complete the sentence, but the direction of his thinking was clear as was his Eisenhower-type assumption that using nuclear weapons represented crossing a line.

In this conversation, Kennedy and Danish Foreign Minister Per Haekkerup discussed NATO nuclear issues. When the Danish ambassador mentioned Henry Kissinger's book on nuclear weapons, Kennedy implied that he disagreed with Kissinger's premise that tactical nuclear weapons could be used to prevent further escalation of a conflict. According to Kennedy, "once one resorts to nuclear weapons one moves into a whole new world. There is no way to prevent escalation once the decision is made to employ nuclear weapons." While the United States was formally committed to using nuclear weapons in the event of a Soviet conventional attack on NATO Europe, this statement and Secretary of Defense Robert McNamara's well-known private advice against initiating the use of nuclear weapons underlines the importance that Kennedy attached to building up NATO's non-nuclear forces.[11]

During a discussion of the pros and cons of a European nuclear force, Kennedy made a critical statement about the president's control of nuclear weapons: "from the point of view of logic there was no reason why the President of the United States should have the decision on whether to use nuclear weapons," but that "history had given him this power" tacitly referring to presidential power as commander-in-chief of the armed forces.

The day after he met with Haekkerup, Kennedy participated in an extended discussion of the U.S. military budget during which he reflected on the use of nuclear weapons. Suggesting that nuclear weapons could not be used in a first strike, Kennedy contended that they were only useful for deterrence. Later, after McNamara stated that to hold NATO together U.S. policy had to be one of maintaining nuclear superiority, Kennedy took a skeptical view: "I must say that I'm all for the convention of the day but I think that the chance of using these weapons is ... I don't know ... socially circumscribed, but the chance of using conventional [is] not." Kennedy was implying the existence of a socially determined understanding that nuclear weapons were not usable.

In a striking and often quoted statement during the 1964 presidential campaign, when Republican contender Sen. Barry Goldwater had made statements supporting nuclear weapons in Vietnam, President Lyndon Johnson demonstrated his acceptance of a nuclear taboo. Noting that "modern weapons are not like any other," he declared that a nuclear exchange would kill hundreds of millions and that at the end "our great cities would be in ashes, our fields would be barren, our industry would be destroyed, and our American dreams would have vanished." Determined to make sure that "day never comes," he emphasized the unique character of nuclear weapons: "there is no such thing as a conventional nuclear weapon."

Like President Kennedy, Johnson believed that nuclear weapons use would put the United States in a whole new world. Reminding his listeners that because nuclear weapons had not been used in combat since 1945, a decision to use them would be a "political decision of the highest order" that "would lead us down an uncertain path of blows and counterblows whose outcome none may know." Quoting the biblical book of Proverbs, Johnson cautioned that "any man who shares control of such enormous power must remember that 'He that is slow to anger is better than the mighty; and he that ruleth his spirit is better than he that taketh a city.'"

Part of a series of policy papers on various countries, this review of U.S. nuclear policy in the event of a North Korean/Chinese attack took the nuclear taboo for granted. A key assumption was the existence of a "valid and distinguishable dividing line between conventional and nuclear warfare, and that it will remain in the US interest to maintain this dividing line." Moreover, that it had been twenty years since nuclear weapons had last been used was of great importance: "The longer this period of self-denial lasts the larger will its symbolic meaning become." The "nuclear responsibility" of the major powers not to use the weapons was not only of intrinsic value, it was also important "in terms of its influence on other powers as they gain access to the nuclear club." If one of the nuclear powers uses the weapons first, it will have to "take responsibility before world opinion for unleashing this new dimension of destruction."

If the United States took such a step it "would greatly increase the danger that the uncommitted world and even some present US allies would be repelled into the arms of the Communists, that nuclear weapons would proliferate; and that the risk of general nuclear war would be considerably increased." Further, nuclear use by the United States against an "Asiatic people" would produce a psychological reaction overseas that "would be almost unequivocally severely critical of the US."

Meeting with members of the Board of National Estimates, DCI McCone asked them to consider the implications of the widening of the war in Vietnam through a Chinese intervention and then an initial U.S. use of tactical nuclear weapons against Chinese forces. McCone asked the Board to consider what would happen “as the U.S. goes up this road.” The following month the estimators responded with a somber analysis that considered the implications of nuclear use on U.S. standing in world affairs, its relationship with NATO and Japan, and the reactions of the Communist powers. The analysis drew explicitly on the concept of a nuclear taboo: “in the field of international affairs [there is] probably no more universal opinion than that which holds the use of nuclear weapons to be abhorrent.” Thus, nuclear weapons use by the United States in Vietnam “would be viewed as among the most fearful and fateful events of modern history.”

However the U.S. used the bomb, it would face “widespread and fundamental. revulsion that [it] had broken the 20-year taboo on the use of nuclear weapons.” The resulting “wave of fear and anger” would produce apprehension that “once the taboo had been broken, there would remain no effective barrier to expanded use of such weapons” and that “general nuclear war” had become a possibility. Moreover, nuclear use would “legitimate” the possession of the weapons and U.S. arguments against nuclear proliferation “would lose moral. credit and encounter cynical. reactions.”

The Board of National Estimates report on the implications for the U.S. diplomatic and security position of the use of f nuclear weapons use in Vietnam.

President Richard Nixon's belief in the value of nuclear threats is well known, but he was aware that, in general, nuclear weapons could not be used. During this meeting, Nixon revealed to cabinet members the U.S. military response to North Vietnam's spring 1972 offensive: mining Haiphong Harbor and escalating the bombing of the Hanoi area. In the course of the discussion of bombing plans, where he mentioned the problem of civilian casualties, Nixon briefly discussed nuclear weapons: He did not consider using them to be "necessary" and ruled out their use: "Obviously, we are not going to use nuclear weapons." Implicitly, Nixon saw using them as too dangerous militarily and politically. Nevertheless, he wanted the threat of nuclear use "hanging over" North Vietnam (See page 10 of the PDF).

Controversy over the first use of nuclear weapons in the event of a new Korean war, sparked by recent statements by Secretary of Defense James Schlesinger and President Gerald R. Ford, led Schlesinger to ask the Arms Control and Disarmament Agency for background on U.S. first use policy.⁠[12] The Ford administration was unwilling to make formal commitments against nuclear first use, but ACDA director Iklé cautioned against first use threats. Using language that was consistent with nuclear taboo thinking, he advised Schlesinger that "In the long run, I believe it will be increasingly in the US interest to make the threat of first-use of nuclear weapons less and less accepted as a 'legitimate' use of military power." Instead of moving back to the U.S. position of the 1950s, it should be "absolutely clear that the highest officials in the US Government firmly distinguish between conventional weapons and nuclear ones, whether tactical or strategic."

When Jimmy Carter became president, he stigmatized nuclear weapons by publicly calling for their elimination, although the follow-up was elusive. Soon after his inauguration, Carter requested studies of major cuts in strategic nuclear forces and later proposed discussions with the Soviets of steps to "reduce the dependence of both the U. S. and the Soviet Union on nuclear weaponry, thereby taking a step towards the eventual elimination of such weaponry." This included the possibility of a "joint US-Soviet statement to the effect that neither power would ever use nuclear weapons first unless its territory or its forces or its allies were attacked." The point would be to "highlight the notion that nuclear weapons are designed only for defensive purposes and [to] throw the burden of nuclear responsibility on the party initiating military hostilities." Carter also suggested a joint agreement on no-first use against non-nuclear weapons states.

A formal agreement with the Soviets was never reached, but in a speech at the United Nations General Assembly in October 1977, Carter declared that the United States would not use nuclear weapons except in self-defense against a conventional or nuclear attack on U.S. territory or on U.S. allies. In keeping with longstanding policy, Carter left open the possibility of nuclear first use in a conventional weapons confrontation, but whether he privately thought otherwise remains unclear. In 1978, after the Soviets made a non-use declaration against states that had renounced nuclear weapons, Secretary of State Cyrus Vance made a reciprocal statement, although limiting its applicability to non-nuclear NPT signatories.[13]

During a discussion of still unresolved comprehensive test ban issues with Canadian defense officials and foreign diplomats, Victor N. Mikhailov, deputy head of the Soviet Ministry for Atomic Power and Industry, invoked the nuclear taboo concept of crossing the line by decrying the development of very low-yield "third generation nuclear weapons." Such weapons would have yields in the one- to ten-ton range, which would be far "less dangerous to the ecology" and would "not lead to global catastrophic consequences." That, he suggested, was a danger: "He stressed therefore there might be a temptation to use them, even in local conflict. 'This concerns all of us,' Mikhailov said."

To prevent third-generation weapons from being developed, all nuclear testing had to be banned, according to Mikhailov. "Establishing lower thresholds of ten kilotons, one kiloton or even less than one kiloton would not work since at even very low yields it would be possible to develop improved nuclear weapons." That danger was removed when the Clinton administration participated in negotiating a comprehensive test ban treaty, although it remains unratified by the U.S. Senate.

When asked whether the Soviet Union had developed such weapons, Mikhailov implied that it had: "The Soviet Union is concerned with its safety and tries to follow closely the progress in the field." The Soviets believed that the United States had carried 30 nuclear tests relating to "third generation weapons development."

Ongoing research at the Department of Energy and Los Alamos Laboratory validated Mikhailov's concern (see Document 16) about U.S. development of third-generation, very low-yield nuclear weapons. With the recent Presidential Nuclear Initiative sharply curtailing roles and missions for tactical nuclear weapons, the labs sought ways to keep the weapons relevant. Moreover, the imminent breakup of the Soviet Union raised new questions about future global stability. This presentation to Defense Department officials concerned the possibility of developing very low-yield nuclear weapons that could be used for a variety of post-Cold War conflicts and contingencies. According to the labs, as the sole superpower, the United States needed nuclear weapons for "deterrence," "stability," and "insurance," especially if nuclear-armed Third World adversaries emerged or if dangerous "spill-overs" from the Soviet breakup emerged, such as "Russian imperialism" or the loss of "central control" over Soviet nuclear weapons. Moreover, to "preclude" nuclear proliferation in NATO Europe, the United States would sustain an "extended deterrence" posture through nuclear deployments and programs of cooperation.

For such purposes, the labs sought high-level support for a secure and stable stockpile of non-strategic nuclear forces (NSNF). A new tactical nuclear "triad" was emphasized, with specific roles for air-and sea-launched weapons, including stand-off bombs and airborne short-range attack missiles. A central element of the briefing was the proposal for a family of "very low-yield" nuclear weapons as "counters against Third-world nuclear threats." They would include a 10-ton earth-penetrating warhead, a 100-ton anti-theater ballistic missile, and a 1000-ton (kiloton) battlefield nuclear weapon. The report did not mention testing such weapons, but that very likely remained on the agenda of the labs that produced this briefing.

A report prepared a few months after the December 1991 briefing (see Document 17) developed the line of reasoning for producing new types of nuclear weapons. In the explanation of why the United States had not used nuclear weapons during the 1991 Gulf War, "Foremost" was a tacit, taboo-like prohibition: a "reluctance to employ nuclear weapons at all, especially against a non-nuclear state." Dowler and Howard also pointed to the "clear belief that the destructive power of available nuclear weapons is so great that the peace-loving societies of the world, including our own, might perceive such use as disproportionate to the attack which provoked it." Larger yield nuclear weapons, including tactical nuclear weapons, were "self-deterring" and more or less unusable. The solution was smaller, far less destructive nuclear weapons that could be used against nuclear-armed adversaries: they "might be perceived as being 'usable' against a nuclear-armed tyrant in a third-world crisis" and "add greatly to the overall deterrent capability of our armed forces."

In keeping with that approach, Dowler and Howard developed more or less arbitrary terminology for the spectrum of weapons type discussed in the December 1991 briefing: from "micronukes," equivalent to 10 tons of high explosives and "mininukes," about 100 tons, to "tinynukes" in the 1 kiloton range. The authors saw such weapons as a deterrent, unlikely to be used: "Their mere existence would greatly diminish any possibility that we would ever face a situation where they would be needed." The implication was their existence would constitute a more credible deterrent. Nevertheless, these were the very same types of weapons that had concerned Mikhailov, who concluded the opposite - that there would in fact be a "temptation to use them."