Of all cases of Cold War conflict in
which the United States could have used nuclear weapons, the Vietnam War
provides one of the strongest “tests” of a taboo against their first use. In Vietnam, the United States chose to lose
a humiliating and destructive war against a small, nonnuclear adversary while
all its nuclear weapons remained on the shelf.
During the ten year military commitment to South Vietnam in the 1960s
and 1970s, the United States sustained large losses in men, money and materiel
at tremendous political cost. U.S.
officials repeatedly declared that the United States could not tolerate the
loss of Southeast Asia to communism, and that the war was vital for U.S.
interests, prestige, and security.
As the war escalated, the United
States was willing to maintain policies of great destructiveness. Operation Rolling Thunder, begun in March
1965, continued for three years and dropped more bombs on Vietnam than had been
dropped on all of Europe in WWII. Starting in 1969, B-52 raids demolished vast
areas in North and South Vietnam, Cambodia and Laos. U.S. forces employed herbicides and defoliants to obliterate
croplands and forests, dropped flame throwers and napalm, and eventually mined
Haiphong harbor. It is estimated that
some 3.6 million Vietnamese, both North and South, were killed in the conflict,
and 58,000 Americans.
The Vietnam War also makes a good
case for exploring the role of a taboo because of a widely perceived analogy to
the Korean War among U.S. decisionmakers at the time. In Korea the United States had demonstrated
that, despite its virtual nuclear monopoly, a nuclear power could engage in a
“limited,” nonnuclear war. However,
because of the perceived military and political costs of that war for the
United States, after Korea a great deal of debate took place as to the
feasibility and desirability of fighting another such limited war in the same
way. One popular lesson the Army (along with some
political leaders) learned from the Korean stalemate was “never again a land
war in Asia,” whose real meaning, administration insiders with access to
military planning understood, was “never again a land war against China without
nuclear weapons.” Doctrines of limited nuclear war developed
in the mid-to-late 1950s and early 1960s elaborated the necessity of being
willing and able to employ nuclear weapons in a local or regional conflict, and
in something less than an all-out nuclear exchange.
Had U.S. leaders wished to use
nuclear weapons in Vietnam, there was no lack of warheads nor any shortage of
suitable targets. Ports, landing
places, supply lines, bridges, railways and airfields could all have been hit
decisively with relatively low-yield weapons.
As McGeorge Bundy, national security adviser to presidents Kennedy and
Johnson, later observed, such targets could have been hit with nuclear weapons
“quite possibly with human losses lower than those of the war that was actually
fought.” Further, fear of nuclear retaliation was not
a prominent concern. Bundy recalled,
“Very little, if at all, was [the nonuse of nuclear weapons] for fear that
friends of [North] Vietnam with warheads of their own, Russians or Chinese,
would use some of them in reply.”
Given this context, one of the
remarkable features of the Vietnam War is how little serious thought U.S.
leaders gave to the possibility of using nuclear weapons. Despite the commitment to avoiding defeat,
the prevailing theories of limited nuclear war, and the levels of destruction
wrought upon Vietnam by conventional means, U.S. political and military leaders
never really came close to using nuclear weapons in the conflict. Presidents Kennedy and Johnson gave little
serious consideration to nuclear options and declined to make any nuclear
threats, despite some recommendations to do so. While President Nixon and his national security adviser Henry
Kissinger more actively explored nuclear options, and engaged in vague nuclear
threats, in the end they also did not come close to actually using such weapons
in the conflict.
Still, they were not quite as much
of a non-issue as Bundy portrayed in his majesterial history of nuclear
decisionmaking. In reality, they were an ongoing subtext of
a war that took place in a Cold War context.
The possibility of employing nuclear weapons was discussed in various
meetings of high-level officials before the first major American troop
deployments in March 1965 and at sporadic intervals up through 1972. Both military and political leaders thought
that tactical nuclear weapons would be militarily useful, and even necessary,
if the conflict expanded, and U.S. leaders received recommendations to use them
or threaten to use them from reputable individuals, including Bundy
himself. Also, Nixon and Kissinger
thought about it themselves. The
possible use of tactical nuclear weapons in the war was the occasional subject
of public rumor and speculation, and emerged as an issue in the presidential
campaigns of 1964 and 1968.
Why did U.S. leaders not resort to
use of tactical nuclear weapons to avoid a frustrating defeat and perhaps
shorten the war and save American lives and treasure? Fear of uncontrolled escalation to war with Russia or China is an
important part of the explanation.
However, such risks were highly disputed throughout the war, and
military and most key political leaders endorsed policies that involved risking
war with China if necessary. Given this
situation, political and normative constraints on the use of nuclear weapons
became particularly salient.
Ultimately, while nuclear weapons might have been militarily useful in
the war, it was clear that, by the time the war was fought, they were politically unusable, and for some
officials, even morally unacceptable.
The constraining and constitutive effects of a taboo against first use
of nuclear weapons operated powerfully for U.S. leaders during the Vietnam War,
both for the majority who shared the taboo and for the minority of those who
did not.
Return to Top
The
Johnson Administration and Vietnam
In 1961 President Kennedy had
rejected intervening in the Laos crisis—defying the recommendations of most of
his advisers in doing so---as soon as he realized that U.S. troops would
inevitably be outnumbered on the ground and that U.S. military chiefs would
count on nuclear weapons to redress the balance. The issue of nuclear weapons arose again
under President Johnson in the context of the decision of 1964-65 to intervene
militarily in Vietnam, which culminated in the Rolling Thunder bombing campaign
and the first major introduction of U.S. troops in March 1965. Once the United States had committed troops
to the defense of South Vietnam, the Joint Chiefs of Staff regularly pushed for
major expansions of the war, including nuclear options. The Johnson administration’s most extensive
discussions of nuclear weapons took place during the 1968 siege of Khe Sanh,
but even this did not get far. There
were two sustained critiques of the use of tactical nuclear weapons in the
conflict: Undersecretary of State
George Ball’s famous October 1964 memo, and a recently declassified study
conducted by physicist Freeman Dyson and three other scientists in 1966. Both of these papers came down strongly
against the use of nuclear weapons in the war.
Return to Top
Main
Scenarios for Use of Nuclear Weapons
The main scenario for resort to
nuclear weapons was a major ground war against Chinese and North Vietnamese
troops, although other options were occasionally proposed. Both military and political leaders thought
that use of tactical nuclear weapons in such a war would be likely, and
possibly even required, to avoid defeat.
Although military commanders were at times divided over whether nuclear
weapons would be needed in a wider war, the Joint Chiefs did estimate that
tactical nuclear weapons would be militarily useful, arguing in a memo in March
1964 that “nuclear attacks would have a far greater probability“ of stopping a
Chinese attack than responding with conventional weapons. As a JCS working group put it, “Certainly no
responsible person proposes to go about such a war [against the North
Vietnamese and Chinese], if it should occur, on a basis remotely resembling
Korea. ‘Possibly even the use of
nuclear weapons at some point’ is of course why we spend billions to have
them.” The Joint Chiefs essentially assumed that
Eisenhower era policies remained in force—that the United States had undertaken
to defend many areas on the assumption that nuclear weapons would be used as
necessary and that they would be effective.
Military leaders were unsure, for
example, whether conventional bombing of Chinese supply lines in North Vietnam
would be sufficient and assumed that at least ground forces, and possibly
nuclear weapons, would be required.
Admiral Harry D. Felt, Commander in Chief, Pacific (CINCPAC) believed
that in the event of a major ground war, there was no possible way to hold off
Communist forces on the ground without the use of tactical nuclear weapons, and
that it was essential that U.S. commanders be given the freedom to use them as
the contingency plans assumed. Chair of
the Joint Chiefs General Earle Wheeler opposed using nuclear weapons to interdict
supply lines but thought they would be necessary in a major war against China,
and should be used only in extreme cases such as to save a force threatened
with destruction or to knock out a special target like a nuclear weapons
facility. However, General Maxwell Taylor, who had
served as chairman of the Joint Chiefs and for a while as U.S. ambassador to
South Vietnam, was more doubtful about the need for nuclear weapons.
Top political leaders did go as far
as the Joint Chiefs. But during their deliberations
in 1964-65 over whether to intervene in the war, they raised the issue of
nuclear weapons, and seemed prepared to accept that they must be ready for
their use. The U.S. Ambassador to South
Vietnam, Henry Cabot Lodge, during meetings in April and May 1964, raised the
question of whether nuclear weapons would be needed to defend South
Vietnam. In a meeting on April 27,
Secretary of State Dean Rusk expressed concern about whether this would bring
the Soviets in, and also noted that he had been much struck “by Chiang
Kai-Shek’s strongly expressed opposition to the use of nuclear weapons.” William Bundy, Assistant Secretary of State
for the Far East, suggested that “limited use of such weapons for interdiction,
in unpopulated areas, might be a different story.” Rusk appeared doubtful that
this could be effective, although he allowed that some sort of threats might be
useful.
In November 1964, shortly after
Johnson was reelected president, an interagency task force chaired by William
Bundy was formed to analyze major courses of action for the United States in
Vietnam. In written comments on the
draft papers laying out three options, A, B and C, Bundy asked with regard to
Option B, the most aggressive course of action, “At what stage, if ever, might
nuclear weapons be required, and on what scale? What would be the implications of such use?” He commented, “This is clearly a sensitive
issue. The President may want a more
precise answer than appears in the papers.”
On November 23, the JCS, in a memo
to Secretary of Defense Robert McNamara, criticized option A as inadequate, and
offered their own versions of options B and C which would include “an advance
decision to continue military pressures, if necessary, to the full limits of
what military actions can contribute toward U.S. national objectives.” In the context, the reference to nuclear
weapons was unmistakable. The Chiefs
had argued earlier, on November 10, that the risk of nuclear conflict should
deter Chinese communist intervention, while expressing a clear willingness to
use nuclear weapons should the Chinese intervene.
During
the meeting of the Executive Committee (ExCom) of the NSC on November 24 to
discuss the three options, someone asked whether nuclear weapons might be
used. McNamara said he “could not
imagine a case where they would be considered,” but McGeorge Bundy thought that
under certain circumstances there might be political and military pressure to
consider their use. However, no precise answer was forthcoming,
and the Pentagon Papers narrative
notes after one such inconclusive mention of nuclear weapons that “again, the
point was not really followed up.” The ExCom eventually chose option C’, the
Chiefs’ plan, with some modifications.
The final December 2 draft of the paper (approved by Johnson on December
7) incorporated the Chiefs’ call for aggressive countermoves to North
Vietnamese escalation, but emphasized troop deployments and did not incorporate
the JCS language committing the United States to the full range of military
actions.
While no
nuclear weapons were deployed in Vietnam, they were on board aircraft carriers
and stockpiled in the region, increasing in numbers up through mid-1967. CINCPAC plans for a major escalation of the
war included both nuclear and nonnuclear options. Recently declassified Pacific Command histories confirm the
existence of these nuclear war plans, first revealed in the Pentagon Papers. A U.S. response to Chinese intervention into
hostilities would require implementation of CINCPAC OPLAN 39-65 and/or OPLAN
32-64. In the event of Chinese entry
into the war, Strategic Air Command (SAC) forces would strike selected targets
within China using nuclear and/or nonnuclear weapons, as directed by the JCS. Additionally, when American Marines
arrived in Da Nang in March 1965, they brought eight-inch howitzers that were
nuclear-capable, though they did not have nuclear warheads. It would thus have been relatively easy for
the United States to change the character of the war to a nuclear one.
There were several constraints on
using nuclear weapons, however, including the risk of escalation, political
costs, and moral considerations.
Return to Top
Uncertain Escalation Risks
The most significant material constraint on
using nuclear weapons was the risk of a wider war with China. U.S. leaders worried that a U.S. invasion of
North Vietnam or the use of tactical nuclear weapons there could bring China
into the war. Winning a war against
China might itself require use of nuclear weapons. In a remote but worst-case scenario, this could provoke Soviet
entry into the war, although most U.S. officials judged this unlikely. Thus the United States might be forced to
use nuclear weapons first, with unpredictable, and possibly disastrous,
consequences.
However, political and military
leaders disagreed bitterly over such escalation risks throughout the war. The JCS tended to see them as much lower
than did political leaders, and hence were more willing to endorse aggressive
policies. The Chiefs, along with
commanders in the field, consistently lobbied for expanding the war and
removing limitations on the fighting as the only way to achieve victory. On January 22, 1964, they told McNamara that
the United States “must be prepared to put aside many of the self-imposed
restrictions which now limit our effectiveness, and to undertake bolder actions
which may embody greater risks.” They advocated a vigorous bombing campaign
against North Vietnam and the introduction of U.S. combat forces in both North
and South Vietnam. In response,
McNamara directed them to plan a campaign of covert actions and air and sea
attacks on North Vietnam up to but not including nuclear weapons. The JCS then complained that if China
entered the war nuclear weapons might be needed, and submitted a plan
culminating in a strike at the Chinese atomic production facility that would
produce a bomb in October 1964.
McNamara took a similar aggressive stance on this initially, but then
scaled it back before presenting it to the President.
Former president Eisenhower, called
in for a consultation on Vietnam in February 1965, shortly before the final
decision supporting the first major deployment of American troops, found the
nuclear option entirely reasonable. He
told President Johnson and senior advisers that he thought the Chinese would
not enter the war, but if they did he would use “any weapons required,”
including nuclear weapons if necessary.
He recommended using carrier-based tactical nuclear weapons for “instant
retaliation,” suggesting that they could be used on large troop formations and
supply depots. In his view, this
would not increase the chances of escalation.
Emphasizing the utility of deterrent threats, he recommended threatening
China with nuclear weapons.
Further, as he had done in the
Korean War, he explicitly advocated challenging the taboo on the first use of
nuclear weapons. The United States, he
said, should not be bound by the restrictions of the Korean War, including the
“gentleman’s agreement” on not using nuclear weapons. This would keep the Chinese out of the war. This view was shared by South Vietnamese
leader General Nguyen Khanh, who had told Rusk during Rusk’s visit to southeast
Asia in April 1964 that as far as he was concerned the United States could use
anything it wanted against China. Eager to expand the war to the North, Khanh
had no objections to use of nuclear weapons, noting on another occasion that
decisive use of atomic bombs on Japan had saved not only American but also
Japanese lives.
Eisenhower’s
statements suggest that he, like the JCS, perceived few material constraints on
the use of nuclear weapons––he believed that nuclear weapons would be useful on
the battlefield, saw minimal escalation risks, and demonstrated no evident
concern about long term consequences of their use. He uttered no cautionary words of any kind to Johnson and his
advisers. In his view, the main
constraint on use of nuclear weapons was a political-normative one––the
“gentleman’s agreement”––which he advocated breaking. It might be argued that he was an aging general no longer in the
loop, but his statements are entirely consistent with those he made when he was
president.
Secretary
of State Rusk endorsed Eisenhower’s recommendations to institute a “campaign of
pressure” against North Vietnam, although he did not share Eisenhower’s views
on nuclear weapons. In a strong
personal memo to the President shortly after the meeting with Eisenhower, he
wrote, “Everything possible should be done to throw back the Hanoi-Viet Cong
aggression––even at the risk of major escalation.”
At an NSC meeting in May 1964, Rusk had suggested moving a U.S. division in
Korea to Southeast Asia, and making a public declaration that any attack on
South Korea would be met by the use of nuclear weapons. He believed that if escalation brought about
a major Chinese attack, it would also involve use of nuclear arms, a risk he
was willing to take. But like the
military, Rusk thought the escalation risks were low. He thought that the Chinese leaders were “practical men” who
would act prudently, in part because of the U.S. nuclear arsenal. As he noted to the Romanian foreign minister
in October 1965, “After all, Chinese nuclear capability within the foreseeable
future will always be trivial as compared to that of the U.S.” Nevertheless, Rusk vigorously opposed
bombing near the Chinese border, and, although he found some use for nuclear
threats, unlike Eisenhower, did not actually advocate use of nuclear weapons.
The military’s benign views of the
escalation risks were especially alarming to Undersecretary of State George
Ball, who worried about a protracted ground war with China, which might produce
substantial U.S. casualties. As he
wrote in a famous skeptical memo on U.S. conduct of the war to McNamara, Bundy,
and Rusk in October 1964, “At this point, we should certainly expect mounting
pressure for the use of at least tactical nuclear weapons. The American people would not again accept
the frustrations and anxieties that resulted from our abstention from nuclear
combat in Korea.” Ball worried that the
fact that there was no longer any shortage of suitable nuclear warheads removed
an important material constraint on their
use. “The
rationalization of a departure from the self-denying
ordinance of Korea would be that we did not have battlefield nuclear
weapons in 1950––yet we do have them today.” Given a situation of nuclear plenitude, and
the military’s benign assessment of the consequences of a wider war or using
nuclear weapons, Ball worried that there were few military or material
constraints on the military’s analysis of nuclear options.
Ball and others sensitive to
escalation risks also worried about the uncertain Soviet reaction to a U.S. use
of nuclear weapons. He wrote in his
October 1964 memo, “While one cannot be certain, the best judgment is that the
Soviet Union could not sit by and let nuclear weapons be used against China.” Similarly, in a lengthy memo to Johnson on
the same day as the meeting with Eisenhower, Vice President Hubert Humphrey,
who opposed the 1965 decision to expand the war, cautioned that if a war with
China had been ruled out in 1952-53 when only the United States had a usable
nuclear capability, it would be even harder to justify such a war now. “No one really believes the Soviet Union
would allow us to destroy Communist China with nuclear weapons, as Russia’s
status as a world power would be undermined if she did.” At the Honolulu conference on June 2, 1964,
Rusk had also noted the risk of provoking a nuclear exchange with the Soviets,
“with all that this involved.”
Nevertheless, unlike in previous Cold War crises, during the
Vietnam conflict U.S. military leaders did not think war with the Soviet Union
was imminent, and were not deterred in their conduct of the war by fear of
Soviet entry into the hostilities. This
was due to the Sino-Soviet split and the highly public animosity between the
two communist great powers by the mid-1960s, along with the relative “detente”
between the United States and the Soviet Union in the wake of the 1962 Cuban
missile crisis. Official U.S.
intelligence estimates consistently stated that it was unlikely either China or
the Soviet Union would intervene unless the United States invaded North Vietnam
with a massive show of troops, bombed China, or attacked Soviet supply ships in
Haiphong harbor. A Special National
Intelligence Estimate of October 9, 1964 stated that “We are almost certain
that both Hanoi and Peiping are anxious not to become involved in the kind of
war in which the great weight of US weaponry could be brought to bear against
them. Even if Hanoi and Peiping
estimated that the US would not use nuclear weapons against them, they could
not be sure of this....”
By mid-1965 the administration was
convinced that the Soviet Union’s commitment to long-term improvement of
relations with the West took precedence over its support for North
Vietnam. In spring 1965, after
operation Rolling Thunder had begun, Chinese leader Zhou Enlai signaled to
Washington through the Pakistanis and the British that Chinese forces would not
become involved militarily in Vietnam if the United States refrained from
invading North Vietnam or China and did not bomb the North’s Red River dikes. However, should war break out, even nuclear
weapons would not force them to quit, and the war would have no boundaries.
However, President Johnson was
determined, even obsessed, with keeping the war restrained, a view shared by
McNamara and others, who thought that even if the actual risks of a wider war
were low, the consequences were unacceptable.
The problem was the risk of uncontrolled escalation, which could lead to
possibly catastrophic outcomes. Johnson
and his advisers, veterans of the 1962 Cuban missile crisis, were committed to
limiting as much as possible the geographical area of the conflict and the
volume of force used. Johnson, in
particular, was “haunted by the ceaseless fear” of Soviet and Chinese
intervention.
Still, although escalation concerns played a
role, they were far from determining.
While national leaders clearly wanted to avoid escalation that might
lead to a large conventional or nuclear war, top political and military
officials disagreed strongly over the risks and consequences of escalation. In practice, the fear of defeat in Vietnam
repeatedly made significant risks of escalation acceptable. On February 9, 1965, McGeorge Bundy wrote
Senator Mike Mansfield that the administration was willing to run the risk of
war with China, and implied a willingness to make a sacrifice at least equal to
that of the Korean War. Although
top civilian leaders did not advocate or support use of nuclear weapons,
and although McNamara later remembered himself appalled by the JCS position on
nuclear weapons, at times during 1964-65, comments by him and other civilian
leaders showed a willingness to run risks that might have led to nuclear war
against China, much as the Chiefs were advocating.
Return to Top
Political and Normative Concerns
In the face of uncertainty and disagreement over escalation risks,
political and normative concerns about using nuclear weapons may have become
particularly salient, if not decisive, for many top officials. As in Korea, U.S. leaders worried that,
given world public abhorrence of nuclear weapons––now even stronger than in the
1950s––the use of such weapons in the Vietnam conflict would jeopardize the
U.S. moral and leadership position in the eyes of friends and allies,
especially if the United States used them again on Asians. In a memo to President Johnson,
Undersecretary Ball wrote: “To use
nuclear weapons against the Chinese would obviously raise the most profound
political problems. Not only would
their use generate probably irresistable pressures for a major Soviet involvement,
but the United States would be vulnerable to the charge that it was willing to
use nuclear weapons against non-whites only.”
Indeed, foreign leaders privately and
publicly cautioned against use of nuclear weapons. Chiang Kai Shek, leader of
nationalist China, told Rusk during Rusk’s trip to southeast Asia in April 1964
that he was “opposed in principle” to use of nuclear weapons, “particularly in
settling the China problem.” Returning to Washington, Rusk reported to
the NSC that he had been impressed by Chiang’s “passionate statement” that
“nuclear war in Asia would be wrong.” Chiang’s opposition to use of nuclear
weapons undoubtedly stemmed in part from his concern that Taiwan would be the
most likely object of a Chinese counterattack, probably overwhelming, and
Chiang and his regime would be at risk.
A month later, in Honolulu, Rusk noted that “many free world leaders
would oppose this [use of nuclear weapons].” When the French ambassador to Washington
suggested to Rusk in July 1964 that a nuclear threat might have a “most
sobering effect” on the Chinese, Rusk again responded that Asians, including
“even Chiang Kai Shek, ”were strongly opposed to use of nuclear weapons in
Asia.
Other foreign leaders urging restraint including U Thant, Secretary-General of
the UN, Prime Minister Lester Pearson of Canada, and British prime minister
Harold Wilson. Mounting public opposition to the war gave
U.S. leaders a demoralizing foretaste of the kind of world public outrage that
a use of nuclear weapons might provoke.
But
it was not only the concerns and abhorrence of others that played a role. A nuclear taboo was becoming entrenched
among high officials of the Kennedy and Johnson administrations. President Johnson, especially, was obsessed
with limiting the war. Like Truman
during the Korean War, he abhorred the thought that he might ever have to
consider use of nuclear weapons. His
memoirs make no mention of nuclear weapons being considered in Vietnam. His senior advisers have testified strongly
that by as early as 1964 Johnson was clear in his own mind that he would not
order a first use of nuclear weapons except perhaps in the case of overwhelming
Soviet aggression in Europe. He never
raised with these advisers the question of how far the American people would
support a decision to use the bomb in Vietnam.
Johnson had spoken out strongly
during the 1964 presidential campaign when Senator Barry Goldwater, campaigning
for the Republican presidential nomination in May 1964, suggested in a speech
that tactical nuclear weapons should be treated more like conventional weapons,
and that they should be used in Vietnam.
The previous October, Goldwater had recommended delegating
responsibility for decisions on use of nuclear weapons to military commanders
in the field under some circumstances (Johnson, continuing Eisenhower policies,
had delegated some authority but only under very limited circumstances). In a speech in Detroit on Labor Day, 1964,
Johnson came out strongly against Goldwater’s views. He described the catastrophe of nuclear war and said, “Make no
mistake. There is no such thing as a
conventional nuclear weapon.” He
continued:
For 19
peril-filled years no nation has loosed the atom against another. To do so now is a political decision of the
highest order. And it would lead us
down an uncertain path of blows and counterblows whose outcome none may
know. No President of the United States
can divest himself of the responsibility for such a decision.
The
reference to “19 peril-filled years” is a strong one, and Johnson’s statement
emphasizes both the “tradition of nonuse” and the fear of uncontrollable
escalation. Bundy wrote later that
although there was politics in Johnson’s speech, there was “passionate conviction”
as well. Two factors appeared to be key in Johnson’s
thinking: the long term effect of any
use of the bomb “on the survival of man”––a prudential consideration, and the
desire not to be the first president in twenty years to use nuclear weapons, that
is, to break the powerful “tradition” of nonuse that had now developed––a taboo
consideration. Johnson did not want to
be the president who set the precedent for use of nuclear weapons. For him, it appears, the use of the bomb in
Vietnam was quite literally “unthinkable.”
Many of Johnson’s
advisers––especially Robert McNamara and Dean Rusk––already possessed a set of
strongly held beliefs about nuclear weapons by this point in time. Cold War crises over Berlin and Laos (1961)
and Soviet missiles in Cuba (1962) had already forced them to confront the
possibility of using nuclear weapons.
Appalled by the Eisenhower nuclear doctrine of “massive retaliation,”
Kennedy and his advisers had sought more “flexible” war plans that included
greater emphasis on conventional weapons.
Further, in the early 1960s, an emerging debate among the fledgling
group of civilian arms control analysts on the merits of a “no first use”
policy began to challenge the logic of the prevailing U.S. deterrence policy
based on the threat to use nuclear weapons first.
Under McNamara the Pentagon began to
revise Eisenhower’s Basic National Security Policy (BNSP), but the process
bogged down in several dilemmas, one of which was the puzzling question of
when, if at all, tactical nuclear weapons might be used. It was one of several reasons why there was
never a final agreed BNSP for the Kennedy administration. Walt Rostow, a hawk who took over the process
of revising the plan when he became head of Policy Planning in the State Department
in 1962, found the role of tactical nuclear weapons “a tough nut to
crack.” It remained an unresolved
dilemma because of “differences of view in the Pentagon.” Thus the draft BNSP was simply left with a
statement of the dilemma posed by tactical nuclear weapons: they were extremely important as a deterrent
against massive conventional attack in Europe and elsewhere, but their actual
use could produce civil and human destruction on a vast scale, in some cases
(depending on locale) tantamount to the strategic use of nuclear weapons.
The growing opposition to the policy
of use of tactical nuclear weapons significantly reflected McNamara’s personal
views. From early in his tenure as
secretary of defense, McNamara opposed use of nuclear weapons, viewing them as
morally objectionable and lacking in utility, issues he often ran
together. He had been horrified by the
briefing he received in early February 1961, only two weeks in office, from
General Thomas Power, commander of the Strategic Air Command (SAC), on SIOP-62,
the U.S. plan for nuclear war inherited from the Eisenhower
administration. It called for an
all-out preemptive first strike on the Soviet Union, Eastern Europe and China,
involving a million times as much explosive power as used in Hiroshima, in
response to an actual or merely impending invasion of Europe by the Soviet
Union that involved no nuclear weapons at all. Millions of Chinese would be destroyed for
no obvious reason. Returning to
Washington, McNamara ordered a review of the nuclear stockpile, which
eventually resulted in a unilateral 50% cut in stockpile megatonnage. He also ordered an increase in nonnuclear
capabilities for countering conventional aggression so that the United States
would not be forced to rely on tactical nuclear weapons.
McNamara apparently decided very
early on that the United States should never strike first with nuclear
weapons. This was made clear in policy
documents he sent to the JCS chairman shortly after the war plan briefing that
so disturbed him. He has stated frequently that he privately
advised both Kennedy and Johnson never to initiate the use of nuclear weapons,
and they agreed.
Daniel Ellsberg, a Pentagon planner
who disagreed with McNamara’s strong advocacy of bombing North Vietnam, and who
later became famous for leaking the Pentagon Papers to the press,
nevertheless felt that McNamara shared his strong personal abhorrence of
nuclear weapons. Recalling a private
meeting with McNamara in 1961 in which McNamara spoke with “great passion”
about the dangers of nuclear weapons and U.S. nuclear war plans, Ellsberg wrote
that “he impressed me strongly and positively that day with his conviction that
under no circumstances must there be a first use of U.S. nuclear weapons in
Europe.” He added, “I’ve never had a
stronger sense in another person of a kindred awareness of this situation and
of the intensity of his concern to change it.” After the meeting, McNamara’s assistant told
Ellsberg that Johnson’s thinking on this subject was “not one iota” different
from McNamara’s. This meeting took place even before the 1962
Cuban missile crisis, an event which drove home to McNamara the dangers of
uncontrolled escalation.
Like McNamara, Dean Rusk, Secretary
of State to both Kennedy and Johnson, found nuclear weapons abhorrent. With a background in international law, he
took a strongly principled approach to diplomacy and America’s role in the
world. George Ball, who disagreed with
Rusk’s fairly aggressive views on the war, nevertheless described him as a man
of “extraordinary integrity and selflessness.” According to Rusk, “we never seriously
considered using nuclear weapons in Vietnam.”
He advocated aggressive uses of force but opposed use of nuclear weapons
in Vietnam and elsewhere because of fallout risks, political costs, lack of
good targets in Vietnam, adequate conventional alternatives, but especially
because of the unacceptable killing of civilians. It is clear that Rusk had been impressed by
the opposition to use of nuclear weapons he had encountered during his trips to
Asia. He noted that many Asians seemed
to see an element of racial discrimination in use of nuclear arms. Was it something the United States would do
to Asians but not to Westerners? He wrote later, “Under no circumstances
would I have participated in an order to launch a [nuclear] first strike, with
the possible exception of a massive [Soviet] conventional attack on West
Europe," which he thought unlikely. “The only rational purpose of nuclear weapons is to ensure that no
one else will use them against us.”
These are remarkable admissions from
McNamara and Rusk. In effect, top U.S.
officials harbored private commitments to “no first use,” in part for moral
reasons, despite the fact that such views directly contradicted official U.S.
deterrence policy relying on a threat to initiate use of nuclear weapons. (They also contradicted U.S. plans for
limited war emphasizing first use of nuclear weapons in a conflict with large
Chinese forces in Asia). McGeorge Bundy
wrote later that he believed that McNamara and Rusk would have resigned if
President Johnson had asked for a decision to use the bomb in Vietnam, and that
Johnson “quietly appreciated this.”
Return to Top
The 1964 Ball Memo
The most systematic analysis of the
consequences of using nuclear weapons in Vietnam came from Undersecretary Ball
in his October 1964 memo. While he
again raised the risk of Soviet intervention following any use of nuclear
weapons, his primary emphasis was on the negative political consequences of any such use. The entire passage under the heading “Pressure for Use of Atomic Weapons,” more than a dozen
paragraphs, is devoted to assessing the political costs to U.S. leadership of
any use of the bomb. Nowhere here does
he mention either risks of nuclear retaliation or escalation to a wider war,
nor the military utility of nuclear weapons, which he appears to assume (by
contrast, when he does mention the risk of Soviet intervention in response to a
U.S. use of nuclear weapons, it is in one sentence in the subsequent section on
“Possibility of Soviet Intervention”).
In his analysis, Ball noted the lack
of meaningful distinction between tactical and strategic weapons in the eyes of
the public, and the “profound shock” that would follow any use of nuclear
weapons “not merely in Japan but also among the nonwhite nations on every
continent.” He predicted that “our loss
of prestige” in the non-aligned and less-developed countries would be
“enormously magnified if we were led to use even one nuclear weapon.”
Most significant, however, was an
analysis of the consequences of legitimizing use of nuclear weapons. Ball wrote that if the United States used
such weapons,
“...our
action would liberate the Soviet Union from the inhibitions that world
sentiment has imposed on it. It would
upset the fragile balance of terror on which much of the world has come to
depend for the maintenance of peace.
Whether or not the Soviet Union actually used nuclear weapons against
other nations, the very fact that we had provided a justification for their use
would create a new wave of fear....The Communists would certainly point out
that we were the only nation that had ever employed nuclear weapons in
anger. And the Soviet Union would
emphasize its position of relative virtue in having a nuclear arsenal which it
had never used.”
The consequences of this could not
be overstated, he wrote. The first use
of the bomb by the United States would set back all the progress made in
superpower relations over the previous few years. It would also generate domestic “resentment against a Government
that had gotten America in a position where we had again been forced to use
nuclear power to our own world discredit.”
Ball’s concern about the negative
precedent set by the use of even a single nuclear weapon was not primarily
because it would demonstrate that such weapons were militarily useful, or that
it would invite Soviet retaliation.
Rather, it would suggest that nuclear weapons were legitimate. If the U.S. resorted
to the bomb, the Soviet Union would then feel free to use it “against other
nations.” Legitimizing the use of
nuclear weapons would undermine a major normative inhibition on resorting to
them in war––a major stabilizing factor of successful nuclear deterrence (“the
balance of terror”). In other words, a
shared normative expectation of nonuse was an
essential element of, not an alternative to, stable nuclear
deterrence. Because of this, the
country that broke the tradition of nonuse of nuclear weapons would be
stigmatized as a pariah among nations.
Ball’s memo---or at least parts of
it---was not well-received. Rusk and
McNamara entirely rejected his questioning of the administration’s arguments
for conventional bombing of North Vietnam.
However, it is likely that they were quite sympathetic to his arguments
about nuclear weapons, which accorded substantially with their own views.
Return to Top
Nuclear
Bluffing
Still, there is some evidence that
U.S. officials were not totally averse to making nuclear threats. On
April 22, 1965, just after the first deployment of US troops to Vietnam, and as
the Johnson administration was shifting its focus to a greater effort to win
the ground war, McNamara gave a not-for-attribution briefing to reporters. After reviewing and defending U.S. strategy
in Vietnam, he introduced a new element—a nuclear bluff. A New York Times reporter recorded
his words:
We are NOT
following a strategy that recognizes any sanctuary or any weapons
restriction. But we would use
nuclear weapons only after fully applying non-nuclear arsenal. In other words, if 100 planes couldn’t take
out a target, we wouldn’t necessarily go to nuclear weapons; we would try 200
planes, and so on. But “inhibitions”
on using nuclear weapons are NOT
“overwhelming.” Conceded it would be a “gigantic step.” Quote:
“We’d use whatever weapons we felt necessary to achieve our objective,
recognizing that one must offset against the price”---and the price includes
all psychological, propaganda factors, etc.
Also fallout on innocents.
“Inconceivable” under current circumstances that nuclear would provide a
net gain against the terrific price that would be paid. NOT inconceivable that the price would be
paid in some future circumstances McNamara refuses to predict.”
These remarks created a flap when
they appeared in the newspapers on April 25, and McNamara amended his comments
publicly the next day. “There is no
military requirement for nuclear weapons” in the present and foreseeable
situation, he said, “and no useful purpose can be served by speculation on
remote contingencies.” Yet, as David Kaiser notes, his original
threat could not have been accidental.
While
Eisenhower remained the most steadfast advocate of the utility of nuclear
threats, even McGeorge Bundy toyed with the idea. In a memo to McNamara in June 1965 criticizing a vast increase in
American troops that McNamara was planning, Bundy noted Eisenhower’s nuclear
threats in the Korean War and suggested that the United States “should at least
consider what realistic threat of larger action is available to us for
communication to Hanoi.” He added, “A full interdiction of supplies to North
Vietnam by air and sea is a possible candidate for such an ultimatum. These are weapons which may be more useful
to us if we do not have to use them.” McNamara wrote later that he did not share
Bundy’s views on nuclear weapons and threatening their use, though he did on
everything else—a recollection that is somewhat inconsistent with his behavior
at the time. On December 2, 1965, McNamara referred in a
telephone conversation with Johnson to certain “very dangerous alternatives
that we can’t even put in writing around here, [and] certainly don’t want to
talk to anyone else about.”
The
nuclear bluff may have been what Bundy suggested---a strategy of communicating
seriousness to Hanoi and Moscow. Soviet
leaders indeed got word that U.S. officials were entertaining nuclear options,
a prospect they viewed with the greatest alarm. According to historian Ilya Gaiduk, drawing on newly available
Soviet documents, in summer 1965 Soviet leaders received regular reports that
the United States might resort to nuclear weapons to suppress the insurgency in
South Vietnam. In June 1965, Soviet
intelligence informed the Kremlin that in a conversation with Italian Foreign
Minister Amintore Fanfani, Rusk had admitted that the prospect of using
tactical nuclear weapons in Vietnam was on the agenda of American policymakers. Although it is unclear how reliable the
reporting was, or what exactly “on the agenda” meant, the report apparently
spurred Soviet leaders to consider seriously the question of U.S. readiness to
wage a nuclear war and the Johnson administration’s intentions in this regard. There thus appears to have been some pattern
of nuclear threatmaking, even if it was a bluff.
Return to Top
Taboo
Effects
The nuclear bluffs notwithstanding, it became increasingly clear
that, in contrast to Korea ten years earlier, use of nuclear weapons in Vietnam
was indeed increasingly “unthinkable.”The operation of a nuclear taboo was
visible in variety of ways.Political
leaders rebuffed in outrage overt attempts to erode the taboo, and resisted
even analyzing nuclear options.Such
developments reflected a mounting burden of proof for any use of such weapons.
Not only were top officials
privately opposed to use of nuclear weapons, but––consistent with taboo
thinking––even the mere analysis of such weapons in the de rigueur cost-benefit
fashion for which the Kennedy administration was famous was essentially
taboo. Samuel Cohen, a weapons
physicist at the RAND Corporation who had advocated use of tactical nuclear
weapons in the Korean War, and who was one of the rare enthusiasts for such an
option in the Vietnam War, ran up against the taboo mindset. As he recalled, “anyone in the Pentagon who
was caught thinking seriously of using nuclear weapons in this conflict would
find his neck in the wringer in short order.”
His formerly good relationship with Pentagon officials had plummeted
because of his pro-nuclear weapons views:
“When the Kennedy guys came in, my relationship with the Office of the
Secretary of Defense dropped off to approximately zero. Those in key positions....had no use for my
views.”
In Pentagon war games, such as one
held in September 1964, to determine whether conventional firepower alone would
stop a Chinese intervention in a war in Southeast Asia, the answer the game
produced was probably not. However,
only a minority of the war game’s American leadership voted to use nuclear
weapons to destroy Chinese nuclear production facilities and execute a general
nuclear attack on China.
One
overt challenge to the taboo was the earlier-mentioned attempt by Goldwater
during the 1964 presidential campaign to reintroduce the notion of
“conventional nuclear weapons”––the same notion that Eisenhower and Dulles had
sought unsuccessfully to promote ten years earlier. In May 1964, Goldwater argued publicly that nuclear weapons
should have been used at Dien Bien Phu to defoliate trees, and that, in similar
fashion, “low-yield atomic weapons” should be used as defoliants along South
Vietnam’s borders, along with an expanded conventional bombing campaign of
North Vietnam. The idea drew an
immediate blast from UN Secretary-General U Thant. The Johnson administration went after
Goldwater with devastating effect, running anti-Goldwater TV adds with
antinuclear themes. The Pentagon responded to “Goldwater’s
folly” by describing technical characteristics of nuclear weapons, arguing that
it was absurd to call them conventional weapons. Goldwater persisted that the army possessed very small nuclear
weapons with a fraction-of-a-kiloton blast.
But to no avail. Johnson
responded with his famous Labor Day speech that “there is no such thing as a
conventional nuclear weapon.” McNamara
wrote later of Goldwater, “His statement implied that he saw no real difference
between conventional weapons and nuclear weapons. He went so far as to suggest the president should instruct
commanders in Vietnam to use any weapons in our arsenal. I profoundly disagreed and said so.”
Goldwater’s statements endorsing the
legitimacy of nuclear weapons---like those of Eisenhower and Dulles
earlier---represented a public attempt to challenge the growing taboo on their
use by eroding the line be
