During the Vietnam War, ARC LIGHT was the general term for the use of B-52 heavy bombers to deliver large volumes of bombs to area targets in South Vietnam, beginning in 1966. The term became generic for use of B-52's against targets with no significant air defenses, such as Laos and Cambodia, but other terms, such as Operation LINEBACKER II, were used when the bombers faced heavy opposition.
B-52s were originally designed to deliver single, or small numbers, of nuclear weapons, to heavily defended targets in the Soviet Union and China. For ARC LIGHT, B-52 aircraft, primarily the B-52D model, were given the "Big Belly" modification so they could carry a maximum tonnage of unguided gravity bombs filled with high explosives; the Mark 119 750 pound bomb was most common.
While the term "carpet bombing" has been used to describe ARC LIGHT missions, they were not exclusively used against vaguely defined targets. In some cases, their drops were brought very close to friendly forces, using AN/MSQ-77 COMBAT SKYSPOT electronic guidance from ground controllers.
First deployments, although not operations were to Guam in February 1965. On February 11, bombers and tankers deployed from Mather AFB, California, and Barksdale AFB, Louisiana.
While there was no opposition in the target area, there were still risks of collisions and accidents. Part of this risk came from the very long flights to the targets; the first missions flew from Anderson Air Force Base on Guam, with a one-way distance in excess of 5000 miles. Air refueling, which had its own hazards, was a necessity. Later missions also flew from bases in Thailand.
Finding the target was the greatest challenge. It was one thing to combine ARC LIGHT strikes with a specific, observed ground operation such as the Battle of Khe Sanh, but quite another to aim at presumed truck concentrations along the Ho Chi Minh trail, or against a hidden headquarters such as COSVN.
The original targeting began with secret US operations against the Laotian part of the Ho Chi Minh trail, in 1961. Under Central Intelligence Agency (CIA} direction, Lao nationals were trained to observe and photograph traffic on the Trail . This produced quite limited results, and, in 1964, Project LEAPING LENA parachuted in teams of Vietnamese Montagnards led by Vietnamese Special Forces operating under U.S. MACV-SOG and South Vietnamese Nha Ky Thuat (Strategic Technical Directorate) control.
Much more recent variations use B-52's to drop individual precision-guided munitions, as in Afghanistan. Early techniques still led to fratricide incidents when even guided bombs hit friendly troops. They entered it as given, and the JDAM flew accurately and unfortunately onto its own controller's position. Area bombing was used in Operation DESERT STORM, often deliberately missing the actual troop targets in order to achieve a psychological effect.
There is no question that the ARC LIGHT strikes were greatly feared, as the aircraft flew too high to be seen or heard; survivors in the target areas report their first warning was the world seeming to explode around them. When the impact area was inhabited, the damage often was immense. In his book, LTC Alex Lee of U.S. Marine Corps Force Reconnaissance, hardened after seeing much, would not write about details of a post-strike bomb damage assessment mission to an ARC LIGHT impact area. . On the other hand, North Vietnamese commanders at the Battle of the Ia Drang report that they had prepared sufficiently, digging in and dispersing their troops, that B-52 damage was light, although still terribly frightening.
- James B. Pralle (August 15, 1969), Project CHECO: ARC LIGHT June 1967 - December 1968, p. xii
- Robert M. Kipp (January-February 1968), "Counterinsurgency From 30,000 Feet: The B-52 in Vietnam", Air University Review
- Rosenau, William (2000), Special Operations Forces and Elusive Enemy Ground Targets: Lessons from Vietnam and the Persian Gulf War. U.S. Air Ground Operations Against the Ho Chi Minh Trail, 1966-1972, RAND Corporation
- Theisen, Eric E. (2003). Ground-Aided Precision Strike Heavy Bomber Activity in Operation Enduring Freedom. Air University Press. Retrieved on 2007-11-12.
- Lee, Alex (1996), Force Recon Command, Random House