The US could have won the war at any time if it had deployed atomic weapons.
The argument
The observation that the nuclear option was always available runs through accounts of the Vietnam War, Michael Herr's Dispatches among them, and this argument treats the decision never to exercise it as the strategic failure that decided the outcome. Nuclear weapons can nullify any enemy on the planet. They were the ultimate display of strength the United States possessed, and their use against Northern Vietnam would have annihilated it, ending any possibility of the North Vietnamese communists taking control of the country. Whatever else the war turned on, it was not fought under a constraint of capability. Proposals for using that capability were made at the time and ranged widely in ambition. Some proponents called for the total destruction of the communist forces outright. Others envisaged something more limited and more targeted: Barry Goldwater suggested using low-yield atomic bombs to destroy roads and bridges, disrupt railway services and defoliate forests — that is, to break the logistics and the cover on which the North's campaign depended, rather than to obliterate the country. A senior military officer with close ties to President Lyndon Johnson was quoted suggesting that periodically using a nuclear weapon would be worthwhile simply to keep the other side guessing, treating the threat as an instrument of pressure in its own right. None of these courses was taken, and the war was instead prosecuted by conventional means against an opponent prepared to absorb conventional losses indefinitely. On this argument, that is the decisive point: the United States held an advantage its enemy could not match or answer, declined to bring it to bear, and thereby left itself fighting on terms where victory was not achievable. Because the failure to use its nuclear advantage was a strategic failure of this magnitude, the argument concludes, it is what caused the loss of the Vietnam War.
Context
The only time nuclear weapons have been unleashed in the theatre of war was in Japan in 1945. The United States dropped two nuclear bombs over Hiroshima and Nagasaki, bringing a swift end to the war in the Pacific. There were calls to use the atomic bomb in Vietnam as early as April, 1954. The National Security Council’s Planning Board recommended Eisenhower loaned France a “new weapon” to defeat the Vietminh and secure Vietnam. Later, Nixon used the threat of nuclear weapons in an attempt to bring the Vietnamese communists to the negotiating table. Atomic weapons were a spectre looming in the background of the Vietnam War, but were never deployed.
Premises
Counter-arguments
The best counter arguments to the nuclear option can be found in the 1967 JASON committee’s 60-page report entitled “Tactical Nuclear Weapons in Southeast Asia”. Within it, the committee finds that tactical nuclear weapons would have had limited results in Vietnam. Nuclear weapons are most useful against large massed troops. But the Vietnamese communists didn’t fight the US with massed troops. They used small guerrilla units. Therefore, nuclear weapons would have done little more than conventional bombing campaigns, which were already proving ineffective against an enemy that appeared to disappear into thin air. The JASON committee estimated that to totally wipe out the Northern Vietnamese forces and their supply lines in small tactical attacks (as Goldwater suggested) it would require 3,000 tactical nukes a year. On top of that, the fallout of nuclear weapons would be unpredictable and difficult to control. It could affect the Southern Vietnamese population just as adversely as it would the enemy communists. The use of nuclear weapons also came with significant risk. It could be seen as an escalation of the war effort, and prompt China or the USSR to enter the war.
Rejecting the premises
[Rejecting P1] Destructive capacity is not military utility. Nuclear weapons are effective against concentrated forces, whereas the North fought through dispersed units and supply routes running through neighbouring countries, so the premise assumes a target the war did not present. [Rejecting P2] Advocacy is not evidence of efficacy. The 1967 JASON study, produced for the government, found that tactical use would achieve little more than the conventional bombing already failing, and put the requirement in the thousands of warheads a year — a case against the proposals the premise cites rather than for them. [Rejecting P3] The premise counts non-use as a failure while passing over what restrained it: unpredictable fallout across the South's population and allied forces, and the risk of drawing China or the Soviet Union into the war. A choice that avoided those outcomes is not obviously a strategic error, and no account is given of the alternative the argument prefers.