Operation Linebacker - Build-up and Air Attacks

Build-up and Air Attacks

American and South Vietnamese Air Force (VNAF) aircraft had been supporting the defense (weather permitting) since the inception of the offensive. These strikes were conducted in support of ARVN forces, and included those of the air wings of the carriers Coral Sea and Hancock. The continuing bad weather, however, limited the ability of the U.S. aircraft to assist in stemming the North Vietnamese onslaught. By 6 April, at naval and air bases around the globe, American forces were put on alert and ships and aircraft squadrons began moving toward Southeast Asia.

The U.S. immediately began a rapid build-up of airpower. The Air Force deployed 176 F-4 Phantoms and 12 F-105s from bases in the Republic of Korea and the U.S. to Thailand between 1 April and 11 May in Operation Constant Guard. Between 4 April and 23 May, during Operation Bullet Shot, Strategic Air Command (SAC) dispatched 124 B-52s from the U.S. to Guam bringing the total B-52 strength available for operations to 209. The Navy cut short its in-port period for the carriers Kitty Hawk and Constellation and ordered Midway and Saratoga to augment the fleet so that four or more carrier air wings could conduct missions simultaneously. 7th Fleet assets in local waters was thereby increased from 84 to 138 ships.

U.S. Air Force tactical strikes against North Vietnam north of the 20th parallel were authorized on 5 April under the nickname Freedom Train. The first large-scale B-52 raid directed against the north was conducted on 10 April when 12 B-52s, supported by 53 attack aircraft struck petroleum storage facilities around Vinh. By 12 April, President Nixon had informed Kissinger that he had decided on a more comprehensive bombing campaign which would include strikes against both Hanoi and Haiphong.

The following day 18 B-52s struck Thanh Hoa's Bai Thuong Airfield. Three more days followed before another strike, this time by another 18 bombers in a pre-dawn attack against an oil tank farm outside Haiphong. They were followed by more than 100 tactical aircraft attacking targets around Hanoi and Haiphong during daylight. Between the 6th and the 15th, U.S. aircraft also struck and destroyed the Paul Doumer and Thanh Hóa bridges and the Yen Vien railway marshalling yard. This marked the introduction of laser-guided bombs against strategic targets in North Vietnam. Both bridges had previously been attacked unsuccessfully with conventional bombs and even missiles. The B-52s were then withdrawn from operations in the north, and when they returned in June, their missions would be limited to the southern panhandle.

By mid-month, nearly all of North Vietnam had been cleared for bombing raids for the first time in over three years. Air Force and Navy commanders and pilots were relieved that Nixon (unlike President Johnson) left the operational planning to local commanders and loosened the targeting restrictions that had hampered Operation Rolling Thunder. Between 1 May and 30 June B-52s, fighter-bombers, and gunships had flown 18,000 sorties against formidable AAA defenses with the loss of 29 aircraft.

The U.S. also now began what North Vietnamese historians have described as "using devious political and diplomatic schemes...to cut back the amount of aid being supplied to us by socialist nations." On 20 April Kissinger met secretly with Brezhnev in Moscow. Unwilling to jeopardize increasingly normalized relations with the West and wary of Washington's growing relationship with Beijing, Brezhnev agreed to apply pressure to Hanoi to end the offensive and negotiate seriously.

Brezhnev then arranged for another secret meeting between Kissinger and Hanoi's lead negotiator Le Duc Tho, to be held on 2 May in Paris. On the assigned day, the two men met for a session that Kissinger later described as "brutal and insulting." The North Vietnamese, sensing victory, were in no mood to make concessions. As a result of this meeting and the fall of Quang Tri City, Nixon was prepared to up the ante, stating that "the bastards have never been bombed like they're going to be bombed this time."