Origins of the campaign
Operation Rolling Thunder was the sustained American bombing campaign against North Vietnam. It began in March 1965, after the Johnson administration decided that the earlier, limited reprisal raids following the Gulf of Tonkin episode and attacks on American bases should become a continuing programme. Its formal end came on 1 November 1968, after President Johnson announced a complete halt to bombing of the north in the last days of October. A partial restriction, covering the area north of the 20th parallel, had been announced on 31 March 1968.
The aims shifted over time and were never wholly agreed. Officials hoped to persuade Hanoi to stop supporting the insurgency in the south, to reduce the flow of men and supplies down the routes through Laos and Cambodia, and to raise the morale of the South Vietnamese government. Some thought of the bombing as a form of gradual pressure, applying more force step by step to make the cost of continuing visible. Others saw it chiefly as a signal. The result was a campaign in which the means and the goals did not always match.
How the bombing was run
One of the unusual features of Rolling Thunder was the degree of civilian control. Targets were chosen in Washington, often at weekly meetings of the president and his senior advisers, which became known informally as the Tuesday lunches. The aim was to prevent the war from widening into a confrontation with China or the Soviet Union, and so restrictions were placed on what could be hit. Areas around Hanoi and the port of Haiphong, as well as a buffer zone near the Chinese border, were at various times off limits or tightly controlled. Pauses in the bombing were sometimes ordered to give diplomacy a chance.
Military commanders chafed at these limits. They argued that gradual escalation gave North Vietnam time to repair damage, build defences and adapt, while civilian officials argued that striking sensitive targets risked triggering a wider war. This disagreement continued throughout the campaign and was one reason that relations between the Joint Chiefs and the Defense Department were strained.
Targets and tactics
Early targets included military barracks, ammunition depots, bridges, roads and railways. In the summer of 1966, American aircraft attacked fuel storage facilities around Hanoi and Haiphong, a step that was publicised as a major escalation. In 1967 the list widened to include more industrial sites, power plants and airfields, together with the bridges and rail links that connected Hanoi to China. The Paul Doumer Bridge at Hanoi was attacked in 1967. By then the strikes were also reaching places closer to the capital than before.
The aircraft were flown by the Air Force and by the Navy from carriers in the Gulf of Tonkin. They included heavily loaded fighter-bombers such as the F-105 Thunderchief. North Vietnam responded by building one of the densest air defence systems in the world, relying on anti-aircraft artillery, Soviet-supplied surface-to-air missiles and MiG fighters. American losses were significant, and many aircrew were killed or captured, becoming prisoners held for years. The heavy toll on aircraft and crews was one of the less visible costs of the campaign.
A very large amount of explosives was dropped. The total tonnage is often given as several hundred thousand tons over the three and a half years, more than 600,000 by many accounts, though figures differ by source and method of counting. The bombing also killed North Vietnamese civilians, and Hanoi publicised damage to hospitals, dikes and villages. American officials said that they tried to avoid civilian casualties, but mistakes and collateral damage did occur.
North Vietnam’s response
Rather than being persuaded to negotiate, North Vietnam adapted. Communities dispersed factories and storage, built shelters, repaired roads and bridges by mobilising large labour forces, and moved much of their movement of supplies to night. Soviet and Chinese aid kept arriving. Many outside observers concluded that the bombing hardened the leadership’s resolve and strengthened national feeling. Others argued that it forced Hanoi to divert great resources to defence and repair, which would otherwise have been available for the war in the south.
The debate of 1967
By 1967 the effectiveness of Rolling Thunder was under heavy questioning inside the government. Defense Secretary Robert McNamara became increasingly sceptical. In August 1967, hearings before a Senate subcommittee led by John Stennis allowed senior military officers to complain about the restrictions on the campaign, while McNamara testified that the bombing had not significantly reduced the flow of supplies to the south and that further expansion would not break North Vietnam’s will. The disagreement between the Defense Secretary and the military was very public, and the episode contributed to McNamara’s departure from the Pentagon some months later.
Meanwhile, the bombing was also an issue for the antiwar movement. Demonstrators and critics pointed to civilian suffering. Some officials, meanwhile, tried to use pauses and offers to open talks. In September 1967 Johnson set out a conditional offer to halt bombing if talks would begin promptly and productively, a proposal usually called the San Antonio formula. Hanoi did not accept it.
The end and the evaluation
After the Tet Offensive shook American opinion in early 1968, Johnson restricted the bombing on 31 March and announced he would not seek re-election. Talks began in Paris in May 1968, and the halt was extended to the whole of North Vietnam at the end of October. Bombing of the north resumed in later years, notably in 1972, but under different names and conditions.
Historians remain divided. Supporters of the campaign argue that it imposed real costs, protected the south by destroying some of the north’s capacity, and might have worked better if applied more forcefully and without restraint. Critics argue that a poor agricultural country with outside backers could absorb the damage, that the supply flow depended on small loads moved along hard-to-target trails, and that the political price at home and abroad outweighed the military gains. It is hard to prove what a different approach would have achieved. What is widely agreed is that Rolling Thunder did not produce the political result that its planners hoped for.