Editing Operation Linebacker II (section)

==Prelude==

===Decisions===
Nixon was now working against a January deadline. Kissinger's "peace is at hand" statement had raised expectations of a settlement among the US population. Even weightier on the President's mind was the fact that the new [[93rd United States Congress|93rd Congress]] would go into session on 3 January, and the President feared that the heavily Democratic legislative branch would preempt his pledge of "peace with honor" by legislating an end to the war.<ref name=lw24/>

Also prompting the President toward some form of rapid offensive action was the cost of the force mobilization that had accompanied ''[[Operation Linebacker]]''. The additional aircraft and personnel assigned to Southeast Asia for the operation was straining [[the Pentagon]]'s budget. The cost of maintaining this "augmentation force" totaled over $4 billion by mid-autumn and [[United States Secretary of Defense|Secretary of Defense]] [[Melvin Laird]] insisted that the President request a supplementary defense appropriation from Congress to pay for it.<ref name=lw24>Lipsman and Weiss, p. 24.</ref> Nixon and Kissinger were convinced that the legislative branch "would seize the opportunity to simply write the United States out of the war".<ref>Earl H. Tilford, ''Setup''. Maxwell Air Force Base AL: Air University Press, 1991, p. 253.</ref>

After returning from Paris on 14 December, and after consultations with Nixon, Kissinger fired off an ultimatum to Hanoi, threatening "grave consequences" if North Vietnam did not return to the negotiating table within 72 hours.<ref>Casey 1987, p. 40.</ref><ref>Lipsman and Weiss, pp. 24–25.</ref> On that day, Nixon ordered the reseeding of North Vietnamese ports with air-dropped naval mines and that the [[Joint Chiefs of Staff]] direct the Air Force to begin planning for a bombing campaign (a three-day "maximum effort" operation) which was to begin within 72 hours.<ref>Tilford, p. 254.</ref> Two days after the 16 December deadline had passed, the U.S. bombed Hanoi. Senior Air Force officers James R. McCarthy and George B. Allison stated years later that the operation had been mainly politically driven, as a negotiation tool to "bring the point home".<ref name = 'McCarthy 1'/>

Many historians of the Vietnam War follow the lead of President Nixon, who claimed that Hanoi's representatives had walked out of the talks, refusing to continue the negotiations.<ref>These include Stanley Karnow, ''Vietnam: A History'', p. 652, Marc Leepson, ''Dictionary of the Vietnam War'' p. 228, John Morocco, ''Rain of Fire'' p. 146, and Harry Summers, ''The Vietnam Almanac'', p. 228, and four of the authors of the U.S. military quoted in this article, Gilster, McCarthy and Allison, and Tilford.</ref> Both sides had proclaimed their willingness to continue the talks; however, Hanoi's negotiators refused to set a date, preferring to wait for the incoming Congress.<ref name="Asselin, p. 139"/> The goal of President Nixon was not to convince Hanoi, but to convince Saigon. President Thieu had to be assured that "whatever the formal wording of the cease-fire agreement, he could count on Nixon to come to the defense of South Vietnam if the North broke the cease-fire."<ref>Stephen Ambrose, ''The Christmas Bombings'', New York: Random House, 2005, p. 403.</ref>

===Planning===
[[File:OperationLinebacker--II.jpg|thumb|[[B-52]] bombing crews at [[Andersen Air Force Base]], [[Guam]] being briefed on the operation.]]
In the wake of Operation Linebacker, the U.S. had a force of 207 [[B-52]] bombers available for use in Southeast Asia.<ref>Tilford, p. 224.</ref> A total of 54 bombers (all B-52Ds) were based at [[U-Tapao RTAFB]], Thailand, while 153 were based at [[Andersen Air Force Base]], [[Guam]] (55 B-52Ds and 98 B-52Gs). This deployment comprised nearly half of the Air Force's manned bomber fleet, and [[Strategic Air Command]] (SAC) commanders were initially reluctant to risk the expensive aircraft and their highly trained crews in such an operation; the production line for B-52s had long since been shut down, and losses could not be replaced.<ref>Michel p. 272</ref><ref>Within the administration, the operation was opposed by Secretary of Defense Laird, his deputy, and the Chairman of the Joint Chiefs of Staff, Admiral Thomas Moorer. Ambrose, p. 403.</ref> The use of large numbers of B-52s was unprecedented in the war and the proposed mass attacks on targets within {{convert|10|nmi|km|-1}} of Hanoi "represented a dynamic change in the employment of air resources".<ref>Herman L. Gilster, ''The Air War in Southeast Asia''. Maxwell Air Force Base AL: Air University Press, 1993, p. 75.</ref>

The new operation, given the title Linebacker II, was marked by top-down planning by the SAC headquarters at [[Offutt AFB]]. Due to the restrictive time frame imposed by President Nixon (only three days) and the experience of Linebacker (in which North Vietnamese fighter aircraft had posed the highest threat to the bombers), SAC's plan called for all of the bombers to approach Hanoi at night in three waves, each using identical approach paths and flying at the same altitude.<ref>''Linebacker II'', p. 41. During Linebacker, 14 American aircraft were lost to SAMs, three were lost to AAA fire and MiGs shot down 27. Tilford, p. 241.</ref>

Once the aircraft had dropped their bombs, they were to execute what SAC termed "post-target turns" (PTT) to the west. These turns had two unfortunate consequences for the bombers: the B-52s would be turning into a strong headwind, slowing their ground speed by {{cvt|100|kn|mph+km/h}} and prolonging their stay in the target area and the PTT would point the emitter antennas of their [[Electronic warfare|Electronic Warfare]] (EW) systems away from the radars they were attempting to jam, degrading the effectiveness of the cells, as well as showing the largest radar cross-section to the missile guidance radars.<ref>Brig. Gen. James R. McCarthy and LtCol George B. Allison, Linebacker II, Maxwell Air Force base AL: Air War College, 1979, p. 121.</ref> The aircraft employed had significantly different EW capabilities; the B-52G carried fewer [[Radio jamming|jammers]] and put out appreciably less power than the B-52Ds but had more efficient engines and larger fuel tanks, hence they were assigned to longer range mission routes.<ref name = 'McCarthy6'>McCarthy and Allison, 1979, p. 6.</ref>

===Vietnamese air defense===
At the start of Linebacker II, the air defense missile forces of the Vietnamese People's Army had 36 air defense missile battalions armed with the S-75M Dvina ([[SA-2 Guideline]]) missile system; probably half were involved in this operation.<ref>Patterns and Predictability: The Soviet Evaluation of Operation Linebacker II, by Dana Drenkowski and Lester W. Grau. p. 17</ref> The SA-2 system was first fielded in 1957 and was a fairly obsolete and cumbersome system by 1972 standards.<ref>Patterns and Predictability: The Soviet Evaluation of Operation Linebacker II, by Dana Drenkowski and Lester W. Grau. p. 35</ref> The [[VPAF]] had only 71 operational aircraft. Of these, only 47 aircraft (31 [[MiG-21]]s and 16 [[MiG-17]]s) could be used for air combat. The MiG-19s were made in China and were not used in combat. Only 13 MiG-21 pilots and five MiG-17 pilots were trained for individual night flight in normal and flying in difficult meteorological conditions. Of 194 pilots, 75 (about 40 percent) were young.{{Elaborate|reason='Young' is meaningless. please elaborate this.|date=August 2022}}<ref name="Predictability p. 26"/>