Operation Linebacker II was a complex, multi-service operation over North Vietnam in December 1972. The B-52 missions flown during Linebacker II became the best known B-52 operations of the Southeast Asia War. The first Operation Linebacker was the aerial interdiction campaign to halt the flow of supplies during North Vietnam's Easter Offensive earlier that year. After the communists stalled peace negotiations, the U.S. Air Force gathered an enormous force of B-52s -- 99 B-52Gs and 53 B-52Ds at Guam and another 54 B-52Ds at U-Tapao. To force the communists back into serious peace negotiations, the United States launched Operation Linebacker II. Beginning on the night of Dec. 18 and ending on the 29th, waves of B-52s attacked military targets in Hanoi, Haiphong and other places in North Vietnam with precision bombing.
Initial plans sent long streams of B-52s flying in groups of three through a narrow corridor into North Vietnam to avoid midair collisions at night. For protection from enemy ground defenses, the planners relied upon Wild Weasels attacking surface-to-air missiles (SAMs), F-4 Phantoms dropping radar-disrupting chaff, the B-52s' onboard radar-jamming electronics, and the bombers making a sharp turn away from the target after releasing their bombs. However, these tactics proved flawed because winds blew the chaff away, and the sharp turns pointed the B-52s' electronic jammers the wrong way. Just as importantly, the bombers flew the same routes every night and gave away the element of surprise.
Already knowing the B-52s' route, North Vietnamese fighters reported the bombers' altitude to the SAM crews, who simply launched unguided SAMs to where they predicted the bombers would be. The communists shot down eleven B-52s before operations halted for Christmas.
After complaints, including those from the 17th Air Division commander, Brig. Gen. Glenn Sullivan, reached higher headquarters, Air Force planners changed their tactics. Importantly, the B-52 aircrews regained the element of surprise by approaching their targets from different directions. Losses from SAMs dropped sharply, and only four more B-52s were lost. They paid a high price, but B-52 aircrews dropped over 15,000 tons of bombs on important military targets during Linebacker II and helped force the North Vietnamese back to the peace table.