Operation LINEBACKER I
Operation LINEBACKER I, conducted between April and October 1972, was a U.S. bombing campaign targeted against the specific North Vietnamese infrastructure of the Ho Chi Minh trail, with the operational-level goal of interrupting the supply line to People's Army of Viet Nam (PAVN) conventional troops in the South. It neither attempted to "send signals" as did Operation ROLLING THUNDER, nor to have a decisive effect on the ability of Hanoi to import supplies and put them onto the Trail as did Operation LINEBACKER II.
It was successful in its objective of stopping the ongoing PAVN Eastertide offensive of South Vietnam, by interfering with the logistics necessary to support regular military units in the field. The campaign used both tactical fighter-bombers and B-52 heavy bombers, although the latter were not sent into the heart of the North Vietnamese integrated air defense system, as they were in Linebacker II.While it had a specific military purpose, it also tied to diplomatic action. While the targets themselves formed coherent systems, the intensity of attack reflected U.S. responses to North Vietnamese behavior at the Paris Peace Talks. On May 8, President Richard Nixon went on national television to say
Now, as throughout the past 4 years, the North Vietnamese arrogantly refuse to negotiate anything but an imposition, an ultimatum that the United States impose a Communist regime on 17 million people in South Vietnam who do not want a Communist government. In this speech, he said there would be new military pressures, and specifically mentioned the mining of Haiphong.
There were a number of sub-operations. The first was Operation FREEDOM TRAIN, which limited itself to targets in the immediate vicinity of the Demilitarized Zone (DMZ), as well as suppression of enemy air defense (SEAD) attacks. This began on April 5.
From lessons learned in the Second World War, the more intense attacks attacks were focused on target systems rather than random targets.
The B-52 attacks focused on storage for petroleum, oil and lubricants, which were imported into North Vietnam primarily by sea. This did not significantly slow the attacks, so, on May 8, Navy bombers carried out Operation POCKET MONEY, using another technology new to the war: anti-shipping mines. The escalation was also a response to the People's Army of Viet Nam capture of Quang Tri. North Vietnamese waterways, especially the port of Haiphong were strewn with delayed-activation mines. Nixon announced that the mines would activate on May 11, giving third-country ships, including Soviet ones, time to leave safely.
...Vietnam target lists prior to Linebacker were based on the ability to strike within accuracy parameters, rather than the significance of the target to affect the enemy.... PGMs changed this focus... Destruction of every target engaged was the new expectation; this made Linebacker a more effects based operation from a targeting perspective. Precision made tactical aircraft more capable of inflicting strategic effects. Inflicting strategic effects with PGMs is the true legacy of Linebacker I.
On July 19, Henry Kissinger had yet another secret meeting with Le Duc Tho, and he found the North Vietnamese negotiator to be far more cooperative than in the past.  It was also agreed that the fact of private meetings, in addition to the public and stalemated Paris Peace Talks, would be admitted to the press, but no details released.
Kissinger found that President Nguyen Van Thieu of South Vietnam was, in fact, hesitant to accept some of the North Vietnames conditions to which he had not objected in the past. Thieu simply never expected his enemy to agree.
By the September 15 meeting, Le Duc Tho urged a settlement, although while North Vietnam offered some concessions, the terms were still uacceptable. Kissinger felt in a strong position, because on the same day, Army of the Republic of Viet Nam (ARVN) forces recaptured Quang Tri. The challenge now was getting Thieu to agree.
- Richard M. Nixon (May 8, 1972), Address to the Nation on the Situation in Southeast Asia., American Presidency Project, University of California at Santa Barbara, 147
- Clodfelter, R. Mark a. (1987), Air Power and Limited War: An Analysis of the Air Campaigns against North Vietnam as Instruments of National Policy, doctoral dissertation, University of North Carolina at Chapel Hill, p. 215
- Clodfelter, p. 212
- Karnow, Stanley (1983), Vietnam, a History, Viking Press, p. 645
- Rodman, Robynn C. (April 2006), Hanoi to Baghdad: Linebacker's Impact on Modern Airpower, Air Command and Staff College, Air University, U.S. Air Forcepp. 4-6
- Werrell, Kenneth P. (Spring 1998), "Did USAF Technology Fail in Vietnam? Three Case Studies", Airpower Journal
- Rodman, p. 11
- Henry Kissinger (1973), Ending the Vietman War: A history of America's Involvement in and Extrication from the Vietnam War, Simon & Schuster, pp. 303-304
- Kissinger, p. 318-320