Operation Linebacker Operation Linebacker was the title of a U . S . Seventh Air Force and U . S . Navy Task Force 77 air interdiction campaign conducted against the Democratic Republic of Vietnam ( North Vietnam ) from 9 May to 23 October 1972 , during the Vietnam War . Its purpose was to halt or slow the transportation of supplies and materials for the " Nguyen Hue Offensive " ( known in the West as the Easter Offensive ) , an invasion of the Republic of Vietnam ( South Vietnam ) , by forces of the People ' s Army of Vietnam ( PAVN ) , that had been launched on 30 March . " Linebacker " was the first continuous bombing effort conducted against North Vietnam since the bombing halt instituted by President Lyndon B . Johnson in November 1968 . Nguyen Hue Offensive . At noon on 30 March 1972 , 30 , 000 North Vietnamese troops , supported by regiments of tanks and artillery , rolled southward across the Demilitarized Zone ( DMZ ) that separated the two Vietnams . This three - division force caught the Army of the Republic of Vietnam ( ARVN ) and their American allies unprepared . The PAVN force struck the defensive positions of the Third ARVN Division and threw it into disarray . South Vietnamese forces then fell back , and a race began between both antagonists to the bridges at Dong Ha and Cam Lo . By 4 April , ARVN officers had patched together a defensive line that held the PAVN at bay , but it was only a temporary respite . Although the conventional attack by the North Vietnamese , which included the extensive use of armor and heavy artillery , riveted the attention of the allies on the northern provinces , it was only the first of three such operations that were launched that spring . On 5 April , a PAVN force of 20 , 000 crossed the border from their sanctuaries in Cambodia in another three - division , combined arms force to attack Bình Long Province , north of Saigon . They quickly seized the town of Loc Ninh and then surrounded the town of An Lộc , cutting the road to the capital . On 12 April , the PAVN struck again , this time moving in from eastern Laos and seizing a series of border outposts around Dak To in Kon Tum Province in the Central Highlands . The North Vietnamese then proceeded east toward the provincial seat of Kon Tum . Hanoi had initiated the offensive to coincide with the winter monsoon , when continuous rain and low cloud cover made air support difficult . The initial U . S . response to the offensive was lackadaisical and confused . The Pentagon was not unduly alarmed and the U . S . Ambassador and the commander of U . S . forces , General Creighton W . Abrams , were out of the country . President Richard M . Nixon ' s first response was to consider a three - day attack by B - 52 Stratofortress bombers on Hanoi and the port city of Haiphong . His National Security Advisor , Dr . Henry Kissinger , convinced the president to reconsider , since he did not want to jeopardize the formalization of the Strategic Arms Limitation Treaty ( SALT I ) with the Soviets , that was due to be formalized in May . Another stumbling block to the plan was General Abrams ' desire to utilize the available bombers ( with their all - weather capability ) to support the ARVN defense . Both Nixon and Kissinger considered a plan offered by the Joint Chiefs of Staff to be both unimaginative and lacking in aggressiveness . On 4 April , he authorized the bombing of North Vietnam ( which had been limited to reprisal raids just above the DMZ ) up to the 18th parallel . In order to prevent a total ARVN collapse and to protect American prestige during the upcoming summit meeting with Soviet Premier Leonid Brezhnev , Nixon decided to risk a massive escalation of force . Due to the continuous withdrawal of American forces and the ongoing policy of Vietnamization , at the time of the invasion fewer than 10 , 000 U . S . troops remained in South Vietnam , and most of them were scheduled to leave within the next six months . The number of combat aircraft stationed in Southeast Asia was less than half that of its peak strength in 1968 – 1969 . At the beginning of 1972 , the U . S . Air Force had only three squadrons of F - 4 s and a single squadron of A - 37 s , a total of 76 aircraft , stationed in South Vietnam . Another 114 fighter - bombers were located at bases in Thailand . 83 B - 52 bombers were stationed at U - Tapao RTAFB , Thailand and at Andersen Air Force Base , Guam . The U . S . Navy ' s Task Force 77 ( stationed in the Gulf of Tonkin ) , had four aircraft carriers assigned to it , but only two were available at any one time to conduct operations . Their air wings totaled approximately 140 aircraft . 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 and . 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 Phantom s and 12 F - 105 s 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 and and ordered and 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 Hóa ' 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 bomb s 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 Quảng Trị 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 . " Operation " Pocket Money " . On 27 April , ARVN defenses in Quảng Trị Province began to collapse . Due to conflicting orders from their high command , South Vietnamese units joined an exodus of refugees heading southward , abandoning Quảng Trị City . PAVN forces entered the city on the same day as the meeting between Kissinger and Le Duc Tho . The PAVN offensive had become a massive conventional military operation that was being conducted on three fronts simultaneously , involving the equivalent of 15 divisions and 600 tanks . As the North Vietnamese continued to gain ground in three of South Vietnam ' s four military regions , the U . S . Joint Chiefs of Staff updated their contingency plans ( drawn up before the bombing halt of 1968 ) for the resumption of bombing in the north and recommended it to the president , who approved it on 8 May . Shortly after his inauguration , Nixon had ordered the preparation of a contingency plan , one that would hopefully bring the Vietnam War to an end . Operation " Duck Hook " was to include an invasion of the north itself and included a proposal to mine its major harbors . The plan had been shelved at the time as too extreme , but it was not forgotten . The U . S . Navy had also been updating its own contingency plans for just such a mining operation since 1965 . On 5 May , the president ordered the Joint Chiefs to prepare to execute the aerial mining portion of the " Duck Hook " plan within three days under the operational title " Pocket Money " . At precisely 09 : 00 ( local time ) on 8 May six Navy A - 7 Corsair II s and three A - 6 Intruder s from " Coral Sea " entered Haiphong harbor and dropped 36 1 , 000 - pound Mark - 52 and Mark - 55 mines into the water . They were protected from attack by North Vietnamese MiG fighters by the guided - missile cruisers and , several destroyers including the guided missile destroyer , and by flights of F - 4 Phantoms . The reason for the precise timing of the strike became apparent when President Nixon simultaneously delivered a televised speech explaining the escalation to the American people : " the only way to stop the killing is to take the weapons of war out of the hands of the international outlaws of North Vietnam . " The mines were activated five days after their delivery in order to allow any vessels then in port to escape without damage . Over the next three days other carrier aircraft laid 11 , 000 more mines into North Vietnamese secondary harbors , effectively blockading all maritime commerce . Both before and during " Pocket Money " , Nixon and Kissinger had worried about the Soviet and Chinese reaction to the escalation . Hours before the president ' s speech announcing the mining , Kissinger had delivered a letter to Soviet ambassador Anatoly Dobrynin which outlined the U . S . plan , but which also made clear Nixon ' s willingness to proceed with the summit . The next day , Nixon shook the hand of Soviet Foreign Trade Minister Nikolai Patolichev at the White House . Although both Moscow and Beijing publicly denounced the American operation , they were not willing to jeopardize their thawing relationship with the U . S . and Hanoi ' s requests for support and aid from its socialist allies met with only cool responses . Nixon and Kissinger ' s diplomacy had triumphed and the U . S . was free to act as it pleased . Going North . Operation " Linebacker " , the designation for the new interdiction campaign , would have four objectives : to isolate North Vietnam from its outside sources of supply by destroying railroad bridges and rolling stock in and around Hanoi and northeastward toward the Chinese frontier ; the targeting of primary storage areas and marshalling yards ; to destroy storage and transshipment points ; and finally , to eliminate ( or at least damage ) the north ' s air defense system . With nearly 85 percent of North Vietnam ' s imports ( which arrived by sea ) blocked by " Pocket Money " , the administration and the Pentagon believed that this would cut its final lines of communication with its socialist allies . The People ' s Republic of China alone shipped an average of 22 , 000 tons of supplies a month over two rail lines and eight major roads that linked it with North Vietnam . On 10 May Operation " Linebacker " and Operation Custom Tailor began with large - scale bombing operations against North Vietnam by tactical fighter aircraft of the Seventh Air Force and Task Force 77 . Their targets included the railroad switching yards at Yen Vien and the Paul Doumer Bridge , on the northern outskirts of Hanoi . A total of 414 sorties were flown on the first day of the operation , 120 by the Air Force and 294 by the Navy , and they encountered the heaviest single day of air - to - air combat during the Vietnam War , with 11 North Vietnamese MiGs ( four MiG - 21s and seven MiG - 17s ) and two U . S . Air Force F - 4s shot down . Anti - aircraft artillery and over 100 surface - to - air missile firings also brought down two U . S . Navy aircraft . By the end of the month , American aircraft had destroyed 13 bridges along the rail lines running from Hanoi to the Chinese border . Another four were destroyed between the capital and Haiphong , including the notorious " Dragon ' s Jaw " that spanned the Song Ma River near Thanh Hóa . Several more bridges were brought down along the rail line leading to the south toward the DMZ . Targets were then switched to petroleum and oil storage and transportation networks and North Vietnamese airfields . There was an immediate impact on the battlefield in South Vietnam . Shelling by PAVN artillery dropped off by one - half between 9 May and 1 June . This slowdown was not due to an immediate shortage of artillery shells , but rather to a desire to conserve ammunition . U . S . intelligence analysts believed that PAVN had enough stockpiled supplies to sustain their campaigns throughout the autumn . The intensity of the bombing campaign was reflected by the sharp increase in the number of strike and support sorties flown in Southeast Asia as a whole : from 4 , 237 for all services , including the VNAF , during the month preceding the invasion , to 27 , 745 flown in support of ARVN forces from the beginning of April to the end of June ( 20 , 506 of them flown by the Air Force ) . B - 52s provided an additional 1 , 000 sorties during the same period . The north was feeling the pressure , admitting in the official PAVN history that " between May and June only 30 percent of supplies called for in our plan actually reached the front - line units . " The " Linebacker " missions included the first widespread use of precision - guided munition s , including electro - optical and laser - guided bombs . In addition to interdicting the road and rail system of North Vietnam , " Linebacker " also systematically attacked its air defense system . The North Vietnamese Air Force , with approximately 200 interceptors , strongly contested these attacks throughout the campaign . Navy pilots , employing a mutually supporting " loose deuce " tactical formation and many with TOPGUN training , enjoyed a kill ratio of 6 : 1 in favor of USA in May and June , such that after that the North Vietnamese rarely engaged them thereafter . The Air Force , opposed by MiG - 21 s , MiG - 17 s , and J - 6 s ( the Chinese version of the MiG - 19 ) , experienced a virtual 1 : 1 shoot - down ratio through the first two months of the campaign , as seven of its eventual 24 " Linebacker " air - to - air losses occurred without any corresponding North Vietnamese loss in a twelve - day period between 24 June and 5 July . Air Force pilots were hampered by use of the outdated " fluid four " tactical formations ( a four - plane , two element formation in which only the leader did the shooting and in which the outside wingmen were vulnerable ) dictated by service doctrine . Also contributing to the parity was a lack of air combat training against dissimilar aircraft , a deficient early warning system , and ECM pod formations that mandated strict adherence to formation flying . During August , however , the introduction of real - time early warning systems , increased aircrew combat experience , and degraded North Vietnamese ground control interception capabilities reversed the trend to a more favorable 4 : 1 kill ratio . " Linebacker " saw several other " firsts " . On the opening day of the operation , Navy Lieutenant Randall H . Cunningham and his radar intercept officer , Lieutenant ( j . g . ) William P . Driscoll became the first U . S . air aces of the Vietnam War when they shot down their fifth MiG . On 28 August , the Air Force gained its first ace when Captain Richard S . Ritchie downed his fifth enemy aircraft . Twelve days later , Captain Charles B . DeBellevue ( who had been Ritchie ' s backseater during four of his five victories ) downed two more MiGs , bringing his total to six . On 13 October another weapons officer , Captain Jeffrey S . Feinstein , was credited with his fifth MiG , making him the final Air Force ace . Operation Lion ' s Den . Although " Linebacker " was largely carried out by air , naval forces were also deployed to provide counter battery fire against enemy targets along the Ho Chi Minh Trail and other important logistical areas and in support of ground troops . One such operation was Operation Lion ' s Den , or " The Battle of Haiphong Harbor " . On 27 August 1972 . Vice Admiral James L . Holloway III took with him his ship , the heavy cruiser , the guided missile cruiser , and the destroyers and conducted a brief night raid against the North Vietnamese forces protecting the port of Haiphong . After the bombardment , the ships were threatened by four Russian - built torpedo boats . Joined by two aircraft from the " Coral Sea " , three of the four torpedo boats were sunk . It was one of the few ship - to - ship naval battles of the war . Paris Peace Talks and conclusion . The stalled offensive in the south and the devastation in North Vietnam had helped to convince Hanoi to return to the bargaining table by early August . The meetings produced new concessions from Hanoi which promised to end the deadlock that had plagued negotiations since their inception in 1968 . Gone were Hanoi ' s demands for the ouster of South Vietnamese President Nguyễn Văn Thiệu and his replacement by a coalition government in which the National Liberation Front would participate . The diplomatic impasse was broken and Nixon ordered a halt to all bombing above the 20th parallel on 23 October . This once again placed Hanoi and Haiphong off - limits , and halted " Linebacker " operations . Air Force historian Earl Tilford has written that " Linebacker " was " a watershed in aerial warfare . . . it was the first modern aerial campaign in which precision guided munitions changed the way in which air power was used . " It succeeded , where " Rolling Thunder " had failed , he claimed , for three reasons : President Nixon was decisive in his actions and gave the military greater latitude in targeting ; American airpower was forcefully and appropriately used ; and the immense difference in the technology utilized made " Linebacker " the first bombing campaign in a " new era " of aerial warfare . During and immediately following the PAVN offensive , U . S . Air Force , Navy , and Marine Corps aviators had flown 18 , 000 sorties in the four northern provinces of South Vietnam and dropped 40 , 000 tons of ordnance in the defense of An Lộc . Between March and May , B - 52 sortie rates had climbed from 700 to 2 , 200 per month and the big bombers had dropped 57 , 000 tons of bombs in Quảng Trị Province alone . During " Freedom Train " and " Linebacker " proper , B - 52s had dropped 150 , 237 tons of bombs on the north while Air Force and Navy tactical aircraft had flown 1 , 216 sorties and dropped another 5 , 000 tons of ordnance . From the beginning of " Freedom Train " in April to the end of June 1972 the United States lost 52 aircraft over North Vietnam : 17 to missiles ; 11 to anti - aircraft weapons ; three to small arms fire ; 14 to MiGs ; and seven to unknown causes . During the same time period , the Republic of Vietnam Air Force lost ten aircraft . 63 North Vietnamese aircraft were destroyed during the same time period . North Vietnam claimed that it had shot down 651 aircraft and sunk or set on fire 80 U . S . warships during the operation . " Linebacker " had played a crucial role in blunting the northern offensive by drying up its vital sources of supply . PAVN had evolved into a conventional military force , and such a force depended upon a complex logistical system , which made it vulnerable to aerial attack . By September , imports into North Vietnam were estimated at 35 to 50 percent below what they had been in May , bolstering claims that the campaign had been successful in its interdiction effort . Air Force General Robert N . Ginsburgh , of the Office of the Secretary of the Air Force , summed up the attitudes of U . S . commanders by remarking that " Linebacker " had " a greater impact in its first four months of operation than " Rolling Thunder " had in three and one - half years . " Although Henry Kissinger may have announced that peace was at hand , it was not going to come easily . American bombers would once again return to the skies of North Vietnam in 1972 during Operation Linebacker II before the American commitment to the Vietnam War came to an end . U . S . aircraft losses during Linebacker . Between 10 May and 23 October 1972 , the United States lost a total of 134 aircraft either over the north or as a direct result of Linebacker missions . 104 were lost in combat and 30 were destroyed in operational accidents . Losses by service were : USAF : – " 70 total " USN : – " 54 total " USMC : – " 10 total " References . Published Government Documents Secondary Sources