Boeing B-52D. A 99th Bomb Wing Boeing B-52D enroute to Hanoi during Operation Linebacker II in December 1972.

In his 1832 book On War, Prussian strategist Carl von Clausewitz described war as "continuation of politics by other means." Nowhere was this better illustrated than in the December 1972 bombing raids, dubbed "Linebacker II," on Hanoi in North Vietnam. They were ordered by President Richard Nixon in response to North Vietnam’s exit from peace talks in Paris. Seeing popular and congressional support for the war dwindling, Nixon had hoped that the talks would yield a peace settlement by the end of the year and that the United States could leave Vietnam gracefully. He had to show North Vietnam he would not stand for a delay in negotiations. But Nixon also had to assure the South Vietnamese that the U.S. commitment to them would continue after the departure of American troops. And this had to be done before Congress reconvened in January, when it was certain to cut off funds for the war, effectively ending it. Consequently, Nixon ordered three days of bomber strikes on North Vietnam’s cities, which would be extended if Hanoi still did not return to the talks.  

Because December is monsoon season in Southeast Asia, the Boeing B-52 Stratofortress, with its all-weather bombing capacity, was chosen as the primary aircraft for the campaign. Further, the B-52 was a cornerstone of America’s nuclear delivery triad, which also made it a particularly valuable weapon. Bringing in massive numbers of this weapon was a signal that the United States was serious about returning to the negotiating table. And it also showed that the United States had the strength, power, and stable of weapons needed to continue the war indefinitely. According to national security advisor Henry Kissinger, it was the B-52’s "ability to shake the mind and undermine the spirit" that made it the most desirable weapon for the operation.

 
Operating from Andersen AFB, Guam and later U-Tapao Royal Thai Air Base, the B-52 was a major component of many operations including Linebacker and Linebacker II.

But Nixon was playing a risky game. The psychological boost to North Vietnam that could result from downing a B-52 could encourage it to continue to fight. If too many of the planes that were presented as America’s greatest were shot down, the United States would appear weak, an especially bad image to portray during the Cold War. Just as the bombings of Hiroshima and Nagasaki symbolized America’s nuclear might to the Soviet Union, Linebacker II was to impress the Communist nations with America’s strength. 

The first day of Linebacker II was December 18, 1972, five days after the Paris peace talks broke down. At 2:41 p.m., 129 B-52s took off in three waves from Anderson Air Force Base in Guam. The waves were made up of cells--groups of three B-52s that flew together for electronic countermeasure (ECM) integrity and targeting purposes. They had a large escort: the 7th Air Force and U.S. Navy: KC-135 refuelling planes, F-4 fighter escorts, F-105 Wild Weasels (to attack surface-to-air missile, or SAM, sites), Navy EA-6 and EB-66 radar-jamming planes, search and rescue teams, and F-4 chaff planes. (Chaff planes are planes that release "chaff," strips of metal that are dropped to confuse radar.) 

On the first night, three B-52s were shot down. But 94 percent of the bombs were released over their targets. Because of the operation’s size and the lengthy flights, the last planes from Day One were landing back at Guam as the first planes for Day Two were taking off. Crew debriefings were analyzed as quickly as possible but not quickly enough to incorporate changes for the second day’s plans. So Day Two proceeded along the same lines as Day One. Targets included rail yards, power plants, and storage areas. And because of the low number of casualties on Day Two, operations for Day Three continued in the same way. This was to prove a fatal mistake. 

The American crews were learning the pattern, and were becoming complacent. Unfortunately, the North Vietnamese were also learning the pattern. On the third day, the waves of B-52s approaching Hanoi saw North Vietnam’s MiGs in the distance. But rather than attack, the MiGs reported the Americans’ heading, altitude, and air speed to ground forces.  Heavy SAM activity and anti-aircraft artillery firing directly into the planes’ paths resulted in the deadliest day of the operation: six B-52s were shot down. With the loss of the $8-million bombers leading to congressional and public anger and calls to end the bombings, it began to look as though Hanoi might be able to hold off peace negotiations until Congress returned in January. Nixon, however, still extended the three-day action to an operation of "indefinite" length. Military planners had to find a way to succeed. 

And there were many problems to fix. The bomber waves were each 70 miles (113 kilometres) long. Nicknamed the "elephant walk," the long line was slow, predictable, and an easy target. The "chaff corridor" showed where the bombers would be headed. It was like the "Yellow Brick Road" for SAM operators. And after dropping their bombs, the B-52s left their targets in a steep 180-degree turn that made a large, bright flash on the enemy’s radar screens. 

Although bomber cells date from World War II, they became essential to survival with electronic warfare. B-52s’ ECM worked only when the cell remained together and retained their integrity. Commanders threatened court-martials for anyone who knowingly compromised cell integrity. This tough measure proved justified when two planes, lost on Day Three, had been without full ECM capabilities because they were missing the third plane in their cells (they had aborted for technical reasons). Evasive manoeuvres, the best way to avoid SAMs but also a destruction of cell integrity, were forbidden. 

Evasive manoeuvres also threatened to cause bombing mistakes, leading to civilian casualties. Bomb targeting needed bombs to be released at a certain altitude and location. If any components were changed, the bomb would be off target and might land on civilians. Radar navigators were also ordered to bring their bombs back if they were less than 100 percent sure they were on target, and all maps showed schools, hospitals and prisoner-of-war camps clearly marked.

 
The F-111A in this photo is on display at the U.S. Air Force Museum in Dayton, Ohio. It is marked as it was in 1972-73 when assigned to the 474th Tactical Fighter Wing during Linebacker II operations in Southeast Asia.

In light of the 20,000 tons of bombs that were dropped on the citizens of Hanoi and Haiphong, there were relatively few casualties. Only 1,318 people were killed in Hanoi and 306 in Haiphong, a truly remarkable number. By comparison, during nine days of bombing on Hamburg, Germany, in 1944, less than 10,000 tons were dropped and 30,000 people died.  

North Vietnam spent the 36-hour Christmas stand down restocking their SAM arsenals. They hoped that if they shot down enough bombers and could hold strong until January, the U.S. Congress would reconvene and legislate the end of the war. U.S. Air Force planners spent the holiday completing plans for the next phase of the operation--the targets were airfields and SAM storage and assembly sites. By knocking out the air defences, B-52 losses would be reduced. And the United States would have freedom of the skies, able to attack at will. 

December 26, 1972, was the day the new tactics were put into action. Crews were now allowed to take evasive manoeuvres against SAMs except during the bomb run itself. The sharp post-target turns were changed to long, shallow ones. And most importantly, in place of the elephant walk, crews were given multiple flight paths they could follow to the targets that would still get them there at roughly the same time. The corridors of chaff became clouds--the chaff was dropped in large formations around the target, which were less likely to lead the enemy to the bombers. 

Day Eight was a success--Hanoi blinked and contacted Washington about resuming talks. But Nixon would not call off the bombings until talks had actually resumed. The final two days of Linebacker II encountered only one problem: a lack of suitable targets. Linebacker ended on December 30. On January 23, 1973, the cease-fire was signed, to take effect four days later. 

Many in the air force erroneously believed that if they had been allowed to run a similar bombing mission in 1965, the war would have ended sooner. They failed to recognize that in 1972, the war was winding to an end and the bombing was only the final push. Also, U.S. relations with China and the Soviet Union had changed in the intervening years, and bombing in 1965 would have encouraged them to join the fight, which perhaps would have escalated into a nuclear conflict. The terms of peace had also changed as the United States went from wanting victory to settling for an easy exit. The success of Linebacker II was part tactic, but mostly timing.

 
The USS Ranger, shown in this photo, was one of the carriers participating in Linebacker II. The others were the USS Enterprise, USS Saratoga, USS Oriskany, and USS America.