The US could have won the war at any time if it had deployed atomic weapons.
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.
“There were always the Nukes…”, wrote Michael Herr in Dispatches. Nuclear weapons can nullify any enemy on the planet. They were the ultimate display of strength and would have annihilated Northern Vietnam, ending the possibility of the Northern Vietnamese communists taking control of the country. Some proponents called for the total destruction of the communist forces. Others, like Barry Goldwater, suggested using low-yield atomic bombs to destroy roads and bridges, disrupt railway services, and defoliate forests. A senior military officer, with close ties to President Lyndon Johnson, was once quoted as saying, “it might be a good idea to toss in a nuke from time to time, just to keep the other side guessing.”
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.
The deployment of atomic weapons had brought a swift end to the war in the Pacific during the second world war. Logic suggests it would have done the same in Vietnam.
Enter the technical rejections of the premises here ...