The need for international partners to legitimise external military intervention during the latter half of the twentieth-century is a well-known development. That it was critical to US intervention in Vietnam is often underappreciated. The difficulties confronting US policymakers forging a coalition during the 1960s are nonetheless wholly recognisable today: to encourage political and military support for a conflict that proved deeply divisive.
By Dr Jonathan Colman, for RUSI.org 
It is well known that the United States has had the company of military contingents from other nations in Iraq and Afghanistan, but it is often overlooked that the Vietnam War was also an example of coalition warfare. By 1969, four years after the United States had undertaken a direct combat role in Vietnam and by which point American policymakers were seeking an honourable exit, there were almost 69,000 third country combat personnel present, alongside 550,000 American and 850,000 South Vietnamese troops. However, third country troop contributions fell short of what was desired, with only the Republic of Korea, Thailand, the Philippines, Australia and New Zealand providing soldiers. Moreover, the United States struggled to build a coherent political platform for the alliance, and there was a recognition that the attractions of American largesse featured among the motives of some of the troop-providing countries. As will be seen, the experience of trying to build a coalition in Southeast Asia in the 1960s raises a number of issues that transcend the Vietnam experience..
Building a political and military coalition
Efforts to recruit allies in Vietnam began formally in April 1964, with the 'More Flags' initiative. President Lyndon B. Johnson stated during a press conference that 'we would like to see some other flags' in South Vietnam and that 'we would all unite in an attempt to stop the spread of ... communism in that part of the world'. Johnson, along with officials such as Secretary of State Dean Rusk, strove on various occasions to win recruits when dealing with allied representatives. Initially, the programme was intended to elicit non-combat assistance such as medical, engineering and police support, but by 1965 it had given way to a desire to see third countries engaged in the fighting as well. When it became apparent by the end of that year that there was little prospect of obtaining 'More Flags' in Vietnam, greater emphasis was put on obtaining extra troops from the countries who had already made commitments.
Washington wanted third country support mainly for political rather than military reasons, to strengthen the international and domestic standing of a war whose moral and geopolitical virtues were hotly contested. As well as demonstrating the support of leading allies, contributions from NATO members had the additional benefit of helping to resist domestic pressures for cutbacks in the American troop commitment to Western Europe. The military contributions of countries like Australia and New Zealand were deeply appreciated, but assistance from Asian states had value in the light of the American concern to avoid 'anything that looks like a white man's club in Asia'.
Initially, Washington tried to use the Southeast Asia Treaty Organisation (SEATO) to provide a sound political foundation for the coalition and to give the military campaign greater propriety. However, of the seven member countries (the United States, Britain, France, Australia, New Zealand, Pakistan, the Philippines, and Thailand), three - Britain, France and Pakistan - were not represented in Vietnam. The British would not provide troops, while France and Pakistan did not extend even rhetorical support for the war. The Republic of Korea, the largest contributor after the United States, was not a member of SEATO. So what was intended to be essentially a SEATO coalition became a looser, more ad hoc one, reflecting mere expediency rather than a more coherent rationale.
'Third Country' Reluctance
Many countries gave verbal endorsement of American policy in Vietnam but were reluctant to provide combat support. Probably the main reason for this reticence was that, as one US diplomat noted, most American allies 'didn't quite see the urgency' of the war in Vietnam 'in the same terms that we did'. Some Asian allies in particular felt that because communism in South Vietnam had a popular base of support 'they just didn't want their country in the long run to be associated with having fought against the Viet Cong'. The perception that the communists had a fair chance of victory was vindicated in 1975, with the collapse of the Saigon regime - though American policymakers would have argued that the relatively limited third country support played at least an indirect role in this outcome.
There were other inhibitions among third countries. At the end of 1964 National Security Adviser McGeorge Bundy noted that in Britain there was 'no political base whatever ... in any party' for a military commitment in Vietnam. Although the Federal Republic of Germany was one of the largest economic contributors in support of South Vietnam, there were distinct constraints towards a more substantial involvement involving 'boots on the ground'. In 1964 a German official stated 'military adventures outside our own borders have characterised two disastrous world wars. People still remember and resent that all over the world. So please leave us out.' France, which had suffered its own debacle in Indochina, would not even provide moral support for the Americans, let along commit troops, and pushed for a conference to bring about the neutralisation of Vietnam. Leaders of NATO states simply did not identify their interests with the future of South Vietnam.
There were occasions when American policymakers tried to use economic persuasion to obtain foreign troops. In 1965 at least one White House adviser wanted to provide support for the pound sterling (which suffered periodic crises or 'runs' that required American bailouts) only if the British would send soldiers to Vietnam. However, President Johnson realised that if the British agreed to send troops to Vietnam only under duress then the national and international controversy of America's stand might be inflamed still further should British motivations become public knowledge. Even as late as 1967, though, Dean Rusk remarked 'rather wryly ... that he did think we could help the British' with their financial troubles if only 'they put forces into Vietnam'.
It was not just in relation to the British that American diplomats thought in terms of financial quid pro quos. In 1966, Secretary of Defense Robert McNamara told Johnson that Korean participation in Vietnam would come but only at a price. Seoul had requested 'about $600-$700 million worth of cumshaw [gratuities or bribes] that they wanted from us in order to send that division'. A US diplomat commented that Philippino troops were 'on per diem and there were perhaps other incentives than fighting the fight for freedom'. Early in 1968, Pakistan offered to provide 5,000 civilians to help South Vietnam but only at what McNamara's successor in the Pentagon, Clark Clifford, described as 'an exorbitant price'.
There were non-financial motives for contributing troops, though. Australia and New Zealand chose to cover their own costs, motivated by Cold War concerns about preventing the spread of communism and also by a wish to strengthen security links with the United States in an era in which British power in Asia was declining. The Thai contribution was in part, according to Dean Rusk, 'a gambit to have a larger voice in determining the composition of any future peace conference and related actions, dealing with the command structure, etc'. Seoul relished the political symbolism of sending its army as an independent (if American funded) force to assist the United States. Given their locations, the troop-contributing countries all had a particular strategic interest in the outcome of the war in Vietnam.
Coalition partners: A valuable addition?
Officially, the Pentagon supported the programme to increase third country support, but some military personnel had their reservations. This was mainly because of their experience in allied commands, such as Korea, when 'the care and feeding of these third country elements has always proved more trouble than it is worth'. Yet third country participants did make a useful practical contribution to the defence of South Vietnam. On a visit to Vietnam in 1967, White House adviser Harry McPherson noted that the Korean Marines and Tiger Troop were 'a tough bunch. They have a method of seal and search that is the epitome of war psychology; it is slow, harrowing, and effective'. McPherson was also 'stunned' by the 'soldierly bearing' of the Philippino troops. They had 'an effective civic action project, a med cap [medical capabilities] program, and they are building a large and decent refugee camp'. General Creighton Abrams, Army Chief of Staff from 1968, commented that the Australians 'performed very well', as did the New Zealand contingent. With over 5,000 dead (mainly Korean) between them, third country forces took a notable share of the losses. This amounted to around a tenth of American casualties, and was proportional with the numbers of third country troops in Vietnam.
On the political front, the United States' coalition partners sometimes expressed concerns about the conduct of the war and about the terms of a settlement. Bundy noted in 1965 that 'to hold some of our allies we may need to be a little less rigid' about engaging in talks with the North Vietnamese. A bombing pause as a prelude to negotiations would, among other things, 'ease the domestic pressure' on allies such as the Australians. The Manila conference of troop-contributing countries in 1966 saw wrangling between the United States and its allies over the terms for possible peace discussions. There were different views among the contributors about the likelihood of Soviet and Chinese intervention, an issue of grave concern to strategists in the White House, the State Department and the Pentagon.
To conclude, the campaign to recruit allies in Vietnam can in some ways be seen favourably. For a start, it is natural for states to prefer to wage war as part of a coalition rather than to carry the burden alone. The United States had the politically, if not militarily, successful coalition warfare example of Korea upon which to draw. When 'Free World' efforts involved combat forces from fourteen countries, plus US personnel. Though quid pro quos are sometimes distasteful, implicit or explicit deals feature in all coalitions. The presence of Asian allies went some way in obviating the view, noted by a French diplomat, that 'this war is a matter of white people against yellow people'.
The experience of coalition-building in Vietnam raises further issues. First, while coalitions are often sought for the purposes of burden-sharing and legitimacy, they also invite conflicting interests from coalition partners and inhibit the effective coordination of policy. Burden-sharing may be fine in theory but it can hinder war-planning. Second, it might seem incongruent that even an overwhelmingly superior power like the United States needed allies in order to legitimise its actions. If anything, this indicates the close connection between war and politics, and also points to the potential conflict of interests between winning a war and winning the peace.
Third, the involvement of other countries could not be seen to result from American pressure but had to be apparently 'voluntary' and self-starting. This was bound up with the quest to gain political legitimacy for the US military campaign. Fourth, and perhaps most fundamentally, Washington faced the perennial irony that the more contentious a war, then the greater the political need for allies to help confer legitimacy upon the war. However, the more doubtful the merits of the war, then the less likely other countries would care to be associated with it. The Vietnam recruitment campaign made the United States a supplicant to an array of often-minor states, and achieved only meagre results.
Dr Jonathan Colman is Lecturer in International History at the University of Salford
The views expressed in this article are the author's alone and do not necessarily reflect those of RUSI
 For source references and a detailed examination see Jonathan Colman and J.J. Widén, 'The Johnson Administration and the Recruitment of Allies in Vietnam, 1964-68', History, 94, 4 (December 2009), pp.483-504.
Stanley Robert Larsen and James Lawton Collins, Allied Participation in Vietnam (Washington, 1975)
Robert M. Blackburn, Mercenaries and Lyndon Johnson's 'More Flags': The Hiring of Korean, Filipino, and Thai Soldiers in the Vietnam War (1994)
Lloyd C. Gardner and Ted Gittinger (eds), The Search for Peace in Vietnam (College Station, 2004)