For a quick overview of Operation Linebacker II and its effects on the Vietnam War, read the Christmas Bombing wu instead. This wu concerns itself mainly with the operational and technical aspects of the bombing campaign.
Prior to Linebacker II, the air war in Vietnam had been characterized mainly by micromanagement from Washington and a almost-complete misallocation of Air Force assets. Under President Johnson, target lists and "packages" of aircraft were handled by the White House and largely determined by political criteria1. This led to a paradoxical situation where B-52 strategic bombers were used largely to conduct carpet bombing in support of ground troops while tactical fighter-bombers such as the F-105 were used to hit strategic targets in North Vietnam2.
After President Nixon's re-election in 1972, the gloves came off. American ground forces had been drawn down to 26,000 men: too few to stop the North Vietnamese or stiffen the poorly regarded ARVN. Nixon called on the Air Force to bring the North Vietnamese war machine to a grinding halt. The Air Force responded with a plan to attack North Vietnam's industrial, military, and transportation infrastructure with an around-the-clock air offensive, a radical change from the ground support and interdiction missions previously flown by the bomber wings. Critics were skeptical of the chances for success; thanks to their Soviet patrons, the North Vietnamese boasted one of the toughest air defense systems in the world. Thickets of anti-aircraft guns were supplemented by 26 SA-2 SAM sites, 21 in the Hanoi-Haiphong area alone; these were guided by state-of-the-art radar stations and backstopped by 145 MiG-21 Fishbed fighters.
Unlike previous operations in which Air Force assets had been seconded to the theater commander, Linebacker II was a Strategic Air Command operation from start to finish. 107 B-52D and 99 B-52G bombers were assembled at Andersen AFB in Guam and U Tapao airbase in Thailand; these would be reinforced by FB-111 "Aardvark" medium bombers. In addition, F-105 "Wild Weasel" fighters would fly "Iron Hand" air defense suppression missions against missile and radar sites, while F-4 fighters flew combat air patrol in defense of the bombers and other F-4s followed up the heavy bombers with the first generation laser-guided smart bombs. Navy and Marine pilots also flew missions in support of Linebacker II from the carriers of Task Group 77, using F-4s, A-6 and A-7 attack bombers.
Electronic warfare figured heavily into the planning for Linebacker II. Aside from the aforementioned "Iron Hand" strikes, the B-52Ds had recently been upgraded with new ECM gear, while the B-52Gs had older, less-powerful EW suites, which would make a significant difference in the loss rates. Here also, the Navy would contribute with their EA-6 Prowlers.
The first day of the operation, December 18, came as a shock to the North Vietnamese. They had expected an attack, but the impact of 129 B-52s striking from Guam and Thailand caught them flat-footed. Three airfields, three transportation facilities, and the main Hanoi radio station were pounded by the largest bomber mission since World War II; the Aardvarks struck at nine more targets. Over the next two days, the Air Force, Navy and Marines continued their 24-hour assault, wearing down the North Vietnamese air defense network and exhausting the SAM supply. Nine B-52s were lost, mainly from the unmodified B-52G force, while SAC tail gunners downed two MiG-21s. The remainder of the week saw smaller, thirty-plane strikes launched with light or no losses as tactics continued to evolve and the enemy grew weaker. On December 25, crews stood down to observe Christmas.
This was later regarded as a political and military mistake; the pause allowed the North Vietnamese to restock their depleted SAM inventory and was interpreted as weakness instead of forbearance. When bombing resumed on the 26th, SAC threw the kitchen sink at North Vietnam: 78 B-52s hit Hanoi simultaneously from four directions while 42 more struck Haiphong. F-111 Aardvarks struck the northern airfields, F-4 Phantoms from all three services roamed the skies hunting MiGs and sowing chaff to blind North Vietnamese radars, Wild Weasels hunted down SAM sites and their radars, and Navy attack aircraft struck targets on the coast. Three more days of this treatment shattered the North Vietnamese air defense system and the infrastructure it defended. Where once waves of SA-2 SAMs had risen to assail the B-52s, only occasional potshots with single missiles were launched by the remaining sites; likewise, the Soviet-trained fighter pilots that survived were kept grounded for lack of radar guidance and for fear of the tactically superior F-4 pilots. Radar and communication networks had been completely shut down, and North Vietnam lay wide open to the kind of bombing campaign that had left Japan a smoking ruin 27 years ago.
The North Vietnamese asked to resume negotiations, claiming that the bombing had nothing to do with their decision, but that is a story for another wu.
1: This process is described in David Halberstam's The Best And The Brightest.
2: Excellently described by Colonel Jack Broughton in Thud Ridge and Going Downtown.