This essay was originally published in War: Perspectives from the Engelsberg Seminar, Axess, in collaboration with the Axel and Margaret Ax:son Johnson Foundation in 2015.

In the decades since the Second World War, the United States has repeatedly engaged in military interventionism around the world. In each instance, the key players in the decisions to initiate, expand and perpetuate the use of military force have been the president and his senior national security aides. It was Harry Truman and his top advisers, for example, who made the call to wage war in Korea in 1950. It was Lyndon B Johnson and his lieutenants who did the same with respect to Vietnam in 1964–65. Likewise, the invasion of Iraq in 2003 and the escalation of American military involvement in Afghanistan in 2009 came about because of top-level decisions in the administrations of, respectively, George W Bush and Barack Obama.

But responsibility for war in these and other post-1945 US wars cannot be ascribed solely to the perceptions and actions of senior American officials; it must also be given to other voices in American society, including those who opposed the interventions in question. The circle of responsibility was wide, for in each case the decision for war occurred in a ‘permissive context’.

This may seem a rather ordinary claim, but I suggest that, with respect to the post-1945 era, it’s a crucial and often under appreciated element in American military interventionism. If we’re to understand what Andrew Bacevich has called ‘America’s path to permanent war’, we need to grapple with this permissive environment. And it’s especially notable because this environment, this seeming consensus in favour of the application of military force, masks – in many instances – deep and wide spread uneasiness about the use of that blunt instrument.

Consider the case of the Vietnam War, which became a large-scale struggle for the United States in early 1965 with the dispatch of combat forces and the start of a massive air campaign, and which raged until the so-called fall of Saigon in April 1975. The struggle generated vast physical destruction in large parts of Vietnam, Cambodia and Laos and killed as many as three million Vietnamese. More than 58,000 Americans lost their lives in the war and 304,000 were wounded, over half of them seriously enough to require hospitalisation; 75,000 US veterans were left severely disabled. The turmoil of the fighting caused a wound in the American body politic that is not fully healed, even today, half a century later, and dealt a heavy blow to the nation’s moral authority in world affairs.

The internal record pertaining to US policymaking in 1964–65 is massive and now mostly declassified and it shows deep private misgivings on the part of a great many senior officials about US prospects in the struggle, even with major American ground troops. Thus, for example, the near-unanimous passage in August 1964, of the Gulf of Tonkin Resolution – which gave Johnson wide latitude to wage war in Southeast Asia as he saw fit – obscures the fact that a great many legislators on Capitol Hill privately opposed a large-scale increase in the American commitment. And we’re not talking about just any lawmakers. The most respected, most senior Democratic Party leaders in the country counselled against escalation, including Armed Services Committee chairman Richard Russell, Majority Leader Mike Mansfield, Foreign Relations Committee chairman William Fulbright and Senator and then Vice President Hubert Humphrey. These men constituted the foreign policy leadership on Capitol Hill and they were shrewd political analysts, no less so than the presumed master political strategist, LBJ. They understood full well that middle America would not react well to a long and inconclusive war on behalf of an apathetic ally and that the Democratic Party would ultimately suffer grievous damage in such a situation. And we could talk about a lot of other Democrats and moderate Republicans who shared this dim view of the prospects in the struggle. Meanwhile, vocal proponents of taking the war to North Vietnam were strikingly few in number.

Just how to account for this congressional reticence about speaking up is not altogether easy. Surely it mattered that the Senate Democratic leadership took a deferential and compliant approach. Partly, too, the skittishness resulted from the knowledge among majority Democrats that the president would not look kindly on public opposition to his actions – Lyndon Johnson left little doubt that he expected party members to fall in line and he ordered top advisers to apply pressure on wavering lawmakers. And partly it resulted from the administration’s repeated assurances that it was keeping all options open, that it genuinely wanted a negotiated solution, that it saw real reasons for optimism in the South Vietnamese government’s prospects; these claims caused many doubters to swallow their concerns and profess support for US policy. At the same time, however, there was on Capitol Hill a certain willingness to be deceived, a willingness to be strong-armed by the White House. Many lawmakers were content to avoid responsibility for a policy issue that seemed to be growing more intractable with each passing day and for which few of them had a clear prescription.

Then, after the ground troops began arriving in March and April, a different dynamic took hold, one that would retain its power for the next half-dozen years: legislators now confronted the choice of supporting the policy, or facing the political consequences of ‘abandoning the troops’ in the field. Richard Russell, for one, promptly became a hawk, telling friends that supporting the troops meant supporting the war. Rhode Island Democratic senator Claiborne Pell understood a new day had dawned: from now on, he ruefully remarked, going against Johnson on the Vietnam issue would be ‘like voting against motherhood’.

In the press, too, leading newspapers were disinclined to ask tough questions in the months of decision (and especially after the first ground troops arrived in March 1965), or to investigate deeply the administration’s claims regarding the situation on the ground in South Vietnam and the need to take new military measures. Among the broader public, meanwhile, apathy was the order of day. Most Americans in 1964–65, like most Frenchmen and women before them (France fought its own war against Ho Chi Minh and his Vietnamese revolutionaries, losing in humiliating fashion in 1954), were too preoccupied with their daily lives to give much thought to a small Asian country thousands of miles away. To the extent that they paid attention, they trusted their leaders’ assurances that the outcome in Vietnam was of critical national security importance and that victory would be achieved.

The permissive context extended beyond America’s shores. In the international community, the United States was largely isolated on the Vietnam issue by the end of 1964. Most friendly governments in Asia and Europe were sympathetic to what Washington sought to achieve in Vietnam – to preserve an independent, noncommunist government in the south – and they shared the US desire to check possible Chinese expansion in the region. Nevertheless, with a few exceptions, these governments resisted what, in some cases, was strong and persistent American pressure to become actively involved in the defence of South Vietnam. Deeply sceptical that a lasting military victory against the Vietcong could be achieved (especially in view of the perceived politico-military weakness of the South Vietnamese government and the apathy and war-weariness of the southern populace), many allied leaders also doubted that the outcome in Vietnam really mattered to Western security. Some feared the political implications at home of committing manpower to an overseas struggle whose importance to national security was open to question.

Here, too, however, as with elite US opinion, the leaders in question opted to stay silent, or even to offer rhetorical support for the escalation. Why? In large part because they considered the bilateral relationship with Washington too important to risk jeopardising over an issue they considered of marginal importance. Challenge the Johnson administration on Vietnam and you could find yourself marginalised on the issues that really mattered – European security, say, or trade relations, or nuclear proliferation.

It’s vitally important to note that senior American officials knew all about this domestic and international mood, knew all about the chronic weaknesses of the Saigon regime. It turns out they were anything but optimistic, most of them, about the prospects in the war effort, even with a large-scale ramping up of the US military commitment. Even more remarkable, we now know that many of them had doubts about whether the enterprise was even worth pursuing at all, whether any of it really mattered all that much to American national interests. Indeed, a startling aspect of the war in the period is the pronounced pessimism at the centre of American decision-making. The hubris so often ascribed to US officials is seldom seen, at least with respect to the prospects in the fighting. Lyndon Johnson and his chief lieutenants fully agreed that the military picture was grim and getting grimmer and, though they liked to say that bombing North Vietnam would make a major difference to the situation in the South, deep down they suspected otherwise. They were not optimistic that North Vietnam would succumb to this form of coercion and rein in the southern insurgency and they knew that, regardless, the keys to victory lay below the seventeenth parallel. Even as they dispatched the first contingent of American troops to the war, the president and his men understood that it would bring resentment from many southerners, including leaders in Saigon, and generate charges of ‘colonialism’ from elsewhere in Asia and around the world.

As for the quality of government in South Vietnam, US leaders were no more sanguine than their critics: they knew it was less capable and less popular than ever, permeated with dissension and – in some quarters, at least – not altogether unsympathetic to an early end to the war through a deal with the National Liberation Front.

On occasion, Johnson even allowed himself to question whether the outcome in Vietnam really mattered to US and Western security. ‘What the hell is Vietnam worth to me?’ he despaired to a top aide in 1964. ‘What’s it worth to this country?’ True, at other times, Johnson was quite capable of arguing for the geopolitical importance of the struggle – he was adept at tailoring his Vietnam analysis according to his needs of the moment. But the overall picture that emerges in the massive internal record for 1964-65 is of a president deeply sceptical that the war could be won, even with large-scale escalation, and far from certain that it was necessary even to try.

So why did major war happen? The question has generated immense scholarly debate over the decades and full consensus among historians remains elusive. Nevertheless, three reasons are of paramount importance and seem especially pertinent to the situation today. First, Lyndon Johnson in late 1964 was, to a degree, hemmed in – not merely by fifteen years of steadily growing US involvement in Southeast Asia, but, more importantly, by his own and his advisers use of overheated language to describe the stakes in the struggle and their confidence in ultimate victory. Having declared publicly, time and again, that Vietnam was a vital security interest, they found it extremely hard to back away. Hawks in Congress and elsewhere, they knew, stood ready to noisily read their past statements back to them and to wonder where the steadfastness had gone.

Second, Johnson’s advisory system functioned poorly. His aides intimidated him with their academic pedigrees and their accomplishments and he, in turn, intimidated them with his powerful presence and bullying tactics. Though quite capable of asking probing questions in top-level meetings, he had little patience with those who sought to give probing answers. His demand for loyalty extended to his inner circle of advisers, which, when combined with his towering personality, had a chilling effect on anyone who tried to build support for a contrary policy position. (Undersecretary of State George Ball did argue such a position, one that events would prove to be strikingly prescient, but Ball was a kind of designated in-house dove whose influence was limited.)

Third and finally, Johnson took the plunge because for him, ‘retreat’ from Vietnam was unimaginable. It was the equivalent of ‘tucking tail and running’. His tendency to personalise all issues pertaining to the war, so evident in later years, was actually there from the start, from his initial vow, in late 1963, that he would not be the first US president to lose a war. Johnson saw attacks on the policy as attacks on himself, saw American credibility and his own personal credibility as essentially synonymous. This limited his ability to render objective judgment. He failed to see that the international and domestic context in late 1964 (and especially after his landslide election victory over Republican Barry Goldwater in November) gave him considerable freedom of action on the conflict.

If Vietnam 1964–65 is a standout example of American leaders operating within a permissive context in waging war, it’s far from the only one. In the case of Iraq, 2002–03, for example, most lawmakers of both parties were content in the months prior to the March 2003 invasion to avoid asking tough questions – or, if they did ask them, to quickly add that they too wanted to be ‘tough on Saddam‘. Many more legislators voted against the authorisation to use force (in October 2002) than had voted against the Gulf of Tonkin resolution in 1964, but the White House got the affirmative vote it sought and by a comfortable margin. Some who voted yes – especially Democrats – would later claim that they were not authorising war, but merely giving President George W Bush the ability to use coercive diplomacy to bring Saddam into line (that is, only if Saddam really believed force might come would he comply with the United Nations demands). They were hoodwinked by the administration, they would insist, a claim that, while not untrue, doesn’t exactly reflect well on their moral and intellectual rectitude. None acknowledged that crass political calculation had anything to do with their vote.

In the press, meanwhile, reporters for leading newspapers in the main months of decision accepted with little question administration claims regarding Saddam Hussein’s intentions and capabilities. By and large, they failed to probe beneath the surface, to ask tough questions, to give serious attention to the views of sceptics. Likewise, among the general public, most Americans in these months were content to go along with alarmist White House claims concerning the threat posed by Saddam’s regime. Few legislators reported widespread demands from their constituents to hold more hearings or pressure the administration for more proof that preventive war was needed. University campuses, by and large, were sleepy places in the weeks prior to the invasion.

Finally, it must be asked: is this permissive context immutable? To a degree, perhaps, but not fully, as the Vietnam case shows. One can debate the impact of the anti-war movement during the period of heavy US involvement (1964–73), but there’s no doubt it had an effect over time. It put constraints on what Lyndon Johnson in his final months could do in Vietnam; it limited the military options open to Richard Nixon after he took office as president in January 1969. That is to say, by then the environment was no longer as permissive as it had been in the years before, either in Congress, or in the press, or in public opinion.

Consider, for example, the changed atmosphere on Capitol Hill. Already in late 1968, shortly after the election, a group of Senate doves met in Majority Leader Mike Mansfield’s office, among them Republicans John Sherman Cooper, Jacob Javits and George Aiken, along with Democrats Frank Church, Stuart Symington, Phil Hart and a few others. According to Cooper aide William Miller, the senators avoided specifics but reached agreement on a core proposition: if the war in Southeast Asia could not be stopped, at least one could work for the next best thing– to keep it contained. Subsequently, by carefully choosing issues and by highlighting the Senate’s constitutional obligations regarding foreign policy, the doves could hope to start squeezing the war, working at its margins in order to compress it. With hard work and a bit of luck, it might be possible to increase anti-war sentiment on Capitol Hill and, thereby, shrink the war. The result was a series of amendments, introduced from 1969 to 1972, aimed at curbing further US military involvement in Southeast Asia. The amendments contained weaknesses that allowed Nixon to retain a significant degree of manoeuvrability – even as he embarked on a graduated troop withdrawal, he intensified the bombing of North Vietnam and enemy supply depots in neighbouring Cambodia, hoping to pound Hanoi into concessions; he also expanded the ground war into Cambodia and Laos – over time, they nevertheless reduced his freedom of action on the war.

To be sure, the anti-war movement did not get everything right. Student activists sometimes romanticised the Viet Cong and the Hanoi government and often exaggerated the supposed economic imperatives that lay behind US intervention. But many of the opponents of the war – whether in Congress or in society at large – grasped the essentials of the struggle and drew lessons from it that have utility today: first, that the political utility of military force is really quite narrow; second, that a clear victory of the sort that yields a formal surrender ceremony on the deck of an American warship is very uncommon; third, that counter-insurgency warfare is always an expensive, time-consuming, chancy proposition, especially for a foreign power; and fourth, that exaggerating the stakes in a given war can come back to bite you, can reduce your manoeuvrability and put your own personal credibility on the line, making it hard to back away, even if you want to.

What this essay has tried to suggest is that Vietnam was never merely ‘Johnson’s War’, or ‘Nixon’s War’. In the same way, Iraq cannot simply be termed ‘Bush’s War’. In each case – as in others in the post-Second World War era – responsibility extended to a broader circle. The presidents were the most important players in the equation, but they needed a permissive context in order to proceed. With respect to Vietnam, this finding would have less historical importance were it not for what recent research has demonstrated: that a great many observers in prominent segments of American society had deep doubts about the Vietnam commitment from an early point and were privately opposed to the 1965 Americanisation before it happened. They anticipated disaster ahead should Lyndon Johnson choose to make Vietnam an American war. Yet they stayed largely silent until after the main decisions had been made and policies implemented. Just what would have happened had these influential, well-respected voices worked hard to thwart escalation in the winter and spring of 1965 – or, at least, to insist on a fully-fledged and comprehensive debate on the conflict and its importance – can never be known, but certainly they would have been a powerful voice in any national debate on the issue. And whatever one’s position on the morality and strategic wisdom of the long, bloody and tragic US involvement in Southeast Asia, there can be no denying that such a debate would have benefited everyone involved.