On February 7, 1965, communist forces attacked the U.S. base at Pleiku in South Vietnam, killing eight Americans and wounding 126. In the attack 25 aircraft were destroyed or damaged. Johnson authorized a retaliatory strike against strategic targets north of the DMZ in Operation FLAMING DART.
On February 24, a U.S. bombing operation called ROLLING THUNDER began, with its first strike actually occurring on March 2. The operation became a frequently interrupted bombing campaign that lasted until October 1968. The operation was intended to impress upon Hanoi a sense of American determination in order to get it to end its support for the insurgency in the South and to halt the infiltration of men and supplies into South Vietnam. The targets in the operation included ammunition depots, radar sites, main roads, railroads, bridges, oil facilities, airfields, army bases, and power plants. Over the course of the bombing, the list of targets grew from 94 in early 1965 to 400 by the end of 1967.
Operation ROLLING THUNDER had five phases. During first phase, from March through June 1965, most of the targets were purely military-ammunition depots, bases, and radar sites. The United States wanted to demonstrate to North Vietnam of the seriousness of American intentions. In retaliation, the Viet Cong attacked American air bases in South Vietnam. By the end of the first phase, the operation was marked by interdiction, rather than simple strategic persuasion. During the second phase, from July 1965 through June 1966, the bombing focused on roads, bridges, and railroads. By the end of June 1966, with phase three, the United States bombed oil and petroleum facilities. According to U.S. Commander-in-Chief of the Pacific Admiral Ulysses Grant Sharp, destroying the North's oil facilities would make it difficult for North Vietnam to support the war in the South. By autumn 1966, estimates were that 70 percent of North Vietnam's oil and petroleum storage capacity had been destroyed. Phase four began in October 1966 with a shift to industrial targets and electric power plants. In this phase, targets in Hanoi were struck. After May 1967 sporadic attacks continued on what remained of the industrial infrastructure and the transportation system, but is was clear to Washington that bombing was not having the desired effect. Following the January 1968 Tet Offensive, in March President Johnson, in an effort encourage peace negotiations, limited bombing to areas south to the 19th parallel. Seven months later, in October 1968, Operation ROLLING THUNDER officially ended.
During the operation, more then 643,000 tons of bombs fell on North Vietnam, destroying 65 percent of the North's oil storage capacity and an estimated 60 percent of the power generating capacity. The majority of the 990 American aircraft lost over North Vietnam during the Vietnam War were shot down during ROLLING THUNDER missions. Even so, the effect of the bombing was not apparent on battlefields in the South. Although undoubtedly the bombing made resupply of communist forces in the South more difficult and costly, numbers of men and supplies moving from the North into the South doubled during each year of the operation.
The second strategic bombing campaign was Operation LINEBACKER I, which included the bombing of North Vietnam and the aerial mining of Haiphong harbor. From May 10 to October 23, 1972 U.S. airpower provided close support to the Army of the Republic of Vietnam (ARVN) against a conventional invasion of 14 divisions of People's Army of Vietnam (PAVN) troops, while at the same time attacking transportation systems and military installations, in addition to other important military targets inside the DRV.
The third strategic bombing campaign was Operation LINEBACKER II, and was more extensive than Operation LINEBACKER I. President Richard Nixon initiated Operation LINEBACKER II on December 18, 1972. Its primary objective was to force the North Vietnamese government to returned to the Paris Peace Talks and renegotiate the settlement they had already agreed to but that had been torpedoed by the government of the Republic of Vietnam (South Vietnam). Few targets were off limits in this campaign, which was conducted largely in the Hanoi and Haiphong areas. During the operation, Air Force and Navy tactical aircraft and B-52s commenced bombardment of the North Vietnamese heartland. The B-52s struck Hanoi and Haiphong during darkness hours, with F-111s and Navy tactical aircraft providing diversionary/suppression strikes on airfields and surface-to-air missile sites. Daylight operations were primarily carried out by A-7s and F-4s, bombing visually or with long-range navigation techniques, depending on prevailing weather conditions at target locations.
Navy tactical air attack sorties under LINEBACKER II were centered in the coastal areas around Hanoi and Haiphong. There were 505 Navy sorties in this area during LINEBACKER II. Aircraft of the Seventh Fleet performed the most extensive aerial mining operation in history, blockading Haiphong, Hanoi's major port. The concentrated strikes were carried out against surface-to-air missile and anti-aircraft artillery sites, enemy army barracks, petroleum storage areas, Haiphong Naval and shipyard areas, and railroad and truck stations.
On December 25, 1972, a Christmas Day bombing/tactical air attack recess went into effect, during which none of the US air services flew sorties. Heavy raids around Hanoi resumed the day after the Christmas bombing halt.
The impact of the bombing has been debated, since many of the targets had been destroyed in LINEBACKER I. The attacks had, however, forced the North Vietnamese to fire away virtually all of their surface-to-air missiles, rendering North Vietnam largely defenseless. By December 29, 1972, following 700 nighttime sorties flown by B-52s and 650 daytime strikes by fighter and attack aircraft, the DRV government agreed to return to the conference table and Nixon halted the bombing. LINEBACKER II formally ended on December 29, 1972. Earl Tilford Jr.
Clodfelter, Mark. The Limits of Air Power - The American Bombing of North Vietnam. New York, 1989.; Tucker, Spencer C. Vietnam. Lexington, N.p.: 1999.
Earl Tilford Jr.