Editing Operation Linebacker (section)

==Nguyen Hue Offensive==
{{Further|topic=the PAVN offensive|Easter Offensive}}
At midday on 30 March 1972, 30,000 PAVN troops, supported by regiments of tanks and artillery, rolled southward across the [[Vietnamese Demilitarized Zone|Demilitarized Zone]] (DMZ) that separated the two Vietnams.<ref>Maj. A.J.C. Lavalle, ed. ''Airpower and the 1972 Spring Offensive''. Maxwell AFB AL: Air University Press, 1976, p. 4.</ref> This three-division force caught the [[Army of the Republic of Vietnam]] (ARVN) and their American allies unprepared.<ref>David Fulghum & Terrance Maitland, et al., ''South Vietnam on Trial''. Boston: Boston Publishing Company, 1984, p. 138.</ref> The PAVN force struck the defensive positions of the ARVN [[3rd Division (South Vietnam)|3rd Division]] and threw it into disarray. ARVN forces then fell back, and a race began between both belligerents to the bridges at [[Đông Hà Combat Base|Đông Hà]] and [[Cam Lộ]].<ref name=Melson>{{cite book|last=Melson|first=Charles|title=U.S. Marines In Vietnam: The War That Would Not End, 1971–1973|publisher=History and Museums Division, Headquarters, U.S. Marine Corps|year=1991|url=https://archive.org/details/TheWarThatWouldNotEnd|isbn=9781482384055}}{{PD-notice}}</ref>{{rp|50&ndash;63}}

By 4 April, ARVN officers had patched together a defensive line that held the PAVN at bay, but it was only a temporary respite.<ref>Fulghum and Maitland, p. 141.</ref> Although the conventional attack by the PAVN, 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]].<ref>Lavalle, p. 6.</ref> They [[Battle of Loc Ninh|quickly seized the town of Lộc Ninh]] and then [[Battle of An Lộc|surrounded the town of An Lộc]], cutting the road to the capital.<ref>{{Cite book |last=Andrade |first=Dale |year=1995 |title=Trial by Fire: The 1972 Easter Offensive, America's Last Vietnam Battle |location=New York |publisher=Hippocrene Books|page=73}}</ref>

On 12 April, the PAVN struck again, this time moving in from eastern [[Laos]] and [[Battle of Kontum|seizing a series of border outposts]] around [[Đắk Tô Base Camp|Đắk Tô]] in [[Kon Tum Province]] in the [[Central Highlands (Vietnam)|Central Highlands]].<ref>Fulghum and Maitland, pp. 154–158.</ref> The PAVN then proceeded east toward the provincial capital 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.<ref>Earl H. Tilford, ''Setup: What the Air Force Did in Vietnam and Why''. Maxwell AFB AL: Air University Press, 1991, p. 225.</ref>

The initial U.S. response to the offensive was lackadaisical and confused.<ref>Fulghum and Maitland, pp. 141–142.</ref> [[The Pentagon]] was not unduly alarmed and the [[United States Ambassador to South Vietnam|U.S. Ambassador to South Vietnam]] and [[COMUSMACV|Commander, U.S. Military Assistance Command, Vietnam]], General [[Creighton W. Abrams]], were both out of the country. President [[Richard Nixon]]'s first response was to consider a three-day attack by [[Boeing B-52 Stratofortress]] heavy bombers on Hanoi and the port city of [[Haiphong]]. His [[National Security Advisor (United States)|National Security Advisor]], Dr. [[Henry Kissinger]], convinced Nixon to reconsider, since he did not want to jeopardize the formalization of the [[Strategic Arms Limitation Treaty]] ([[SALT I]]) with the [[Soviet Union]], that was due to be signed in May.<ref>Tilford, p. 234.</ref> Another stumbling block to the plan was Abrams' desire to utilize the available bombers (with their all-weather capability) to support the ARVN defense.<ref>Fulghum and Maitland, p. 170.</ref>

Nixon and Kissinger considered a plan offered by the [[Joint Chiefs of Staff]] to be both unimaginative and lacking in aggression.<ref name="Fulghum and Maitland, p. 142">Fulghum and Maitland, p. 142.</ref> On 4 April, Nixon authorized the bombing of North Vietnam (which had been limited to reprisal raids just above the DMZ) up to the [[18th parallel north|18th parallel]].<ref name="Tilford, p. 228">Tilford, p. 228.</ref> To prevent a total ARVN collapse and to protect American prestige during the upcoming summit meeting with Soviet general secretary [[Leonid Brezhnev]], Nixon decided to risk a massive escalation of force.<ref>Tilford, p. 232</ref>

Due to the continuous withdrawal of American forces as part of the policy of [[Vietnamization]], at the time of the invasion fewer than 10,000 U.S. combat troops remained in South Vietnam, and most of them were scheduled to leave within the next six months.<ref>Michael Casey, Clark Dougan, Samuel Lipsman, Jack Sweetman, Stephen Weiss, et al., ''Flags into Battle''. Boston: Boston Publishing Company, 1987, p. 182.</ref> 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]] (USAF) had only three squadrons of [[McDonnell Douglas F-4 Phantom II]] fighter-bombers and one squadron of [[Cessna A-37 Dragonfly]] light attack aircraft, a total of 76 aircraft, stationed in South Vietnam.<ref>Lavalle, p. 12.</ref> Another 114 fighter-bombers were located at bases in [[Thailand]]. 83 B-52s were stationed at [[U-Tapao International Airport|U-Tapao RTAFB]], Thailand and at [[Andersen Air Force Base]], [[Guam]].<ref>Tilford, pp. 223–224.</ref> The [[U.S. Navy]] (USN)'s [[Task Force 77 (U.S. Navy)|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 had approximately 140 aircraft.<ref>John Morocco, ''Rain of Fire''. Boston: Boston Publishing Company, 1985, p. 170.</ref>