tion, the MACV commander gave some consideration about a change in command relations in the north. He finally decided, as a half measure, to establish a MACV (Forward) headquarters at Phu Bai under his deputy, General Creighton W. Abrams, and prepared the way for single management of Marine air under his deputy for air, Air Force General William Momyer.
While, on 21 January 1968, the Communists initiated a massive bombardment on Khe Sanh, their main offensive thrust was not the Marine base nor the DMZ forces, but the cities and lines of communication throughout South Vietnam from the MeKong Delta in the south to Quang Tri City in the north. Khe Sanh would remain under siege from 21 January until early April. Although making several strong probes, overrunning the Special Forces at Lang Vei, and maintaining large troop formations around the base, the North Vietnamese never launched a full-fledged ground assault against Khe Sanh. Speculation and controversy still dominate the discussion about the siege and the motivation of the North Vietnamese. Did the enemy hope for a replay of Dien Bien Phu, its successful campaign against the French in 1954, or merely use Khe Sanh as a feint for his Tet offensive? Given the number of troop resources that the enemy placed around Khe Sanh and the pounding they absorbed from artillery and air, there can be no doubt that the North Vietnamese would have taken the base, if they could have done so. On the other hand, there was a limit on the price they were willing to pay, and in all probability, Khe Sanh was only one objective among many. The Communists hoped and possibly believed that their Tet offensive would bring about a true people's revolution against the South Vietnamese regime, resulting in the defection of the ARVN and the fall of the government.
Arguably, however, the Communists may never have realistically expected their Tet offensive to cause an uprising throughout South Vietnam and probably had in mind a more limited and attainable goal. A case could be made that at least in I Corps, their main objective was not Khe Sanh, but Hue. They perhaps hoped that the capture of Hue would result in the defection of the South Vietnamese forces and the loss of other population centers in the two northern provinces of South Vietnam. Such a result would have cut the allied lines of communication and left the 3d Marine Division suspended without support in the northern regions bordering the DMZ and Laos. This would have left the Communists in a strong position for obtaining their own terms. Given both the resources that the North Vietnamese put into the battle and the tenacity with which they fought, it was obvious that the Hue campaign was a major component of the entire Tet offensive. According to an enemy account, the North Vietnamese military command in planning the offensive took into consideration that the U.S. and South Vietnamese had concentrated their forces in the north, expecting an attack along Route 9. It viewed Hue as the weak link in the allied defenses in the northern two provinces.
The battle for Hue was a relatively near thing. Only the failure of the North Vietnamese to overrun the Mang Ca and MACV compounds permitted the allies to retain a toehold in both the Citadel and the new city. With the holding of these two positions, the Americans and South Vietnamese were able to bring in reinforcements to mount a counreroffensive. Even then, if the enemy had blown the An Cuu Bridge across Route 1 on the first day, the Marines would not have been able to send in their initial battalions and supplies into the city. If the enemy had made a stronger effort to cut both the water and land lines of communications, the outcome of the struggle for Hue would have been less predictable. The Marine rapid response and quick adaptability to street fighting together with the fact that the South Vietnamese forces did not defect permitted the allied forces to attain the upper hand. Fortuitously, the 1st Air Cavalry Division had arrived in northern I Corps prior to Tet and was eventually able to commit four battalions to the battle. By the end of February, the allies controlled Hue.
With the securing of the city of Hue, the enemy's countrywide Tet offensive had about spent itself. While the enemy offensive failed, public opinion polls in the United States revealed a continuing disillusionment upon the part of the American public. President Johnson also decided upon a change of course. On 31 March, he announced his decision not to stand for reelection, to restrict the bombing campaign over North Vietnam, and to authorize only a limited reinforcement of American troops to Vietnam.
Notwithstanding the mood in Washington and ready to begin his counter-offensive, General Westmoreland altered again his command arrangements in I Corps. On 10 March, he disestablished his MACV (Forward) Headquarters. He replaced it with Provisional Corps, later XXTV Corps, whose commander, an Army lieutenant general, was directly subordinate to III MAF. At the same time, however, General Westmoreland designated the Seventh Air Force commander, as "single manager for air" and gave him "mission