Events in Hanoi Preceding the Tet Offensive
The U.S. "search and destroy" war of attrition in South Vietnam and the "Rolling Thunder" aerial bombardment of North Vietnam had produced massive casualties in the South, widespread destruction of industrial, transportation and military infrastructure in the North, and a stalemate on the Southern Vietnamese battlefield. This caused a sharpening of existing differences among Vietnam Workers' Party (the precursor of the Communist Party of Vietnam) leaders over how to carry out the struggle to unite Vietnam under their rule.
The Question in Hanoi: South First or North First?
Relative moderates were known as the North First faction. They advocated a patient approach, focusing on developing the the North Vietnamese economy while giving the People's Army of Vietnam (PAVN) a chance to become well-trained and equipped with modern weapons. A stable and strong North Vietnam would, they envisioned, subdue the South Vietnamese "puppet state" politically and diplomatically. Radicals believing that only armed struggle could unify the nation formed the South First faction. They called for aggressive action in order to bolster morale among Communist forces in the South.
In relations with the "imperialist" world, the moderates leaned towards the Soviet Union and its strategy of peaceful coexistence. They called for a return to protracted guerrilla insurgency in the South while negotiating an end to the United States' bombing of North Vietnam. The militants favored the approach of the People's Republic of China, rejecting the proposition of negotiating an agreement with the U.S. The South First faction wanted to achieve a quick victory, in order to break the stalemate in the South.
On military strategy, the foremost proponent of having PAVN take the initiative in South Vietnam was Nguyen Chi Thanh. Thanh led the Central Department of South Vietnam (COSVN), through which the Hanoi-based Vietnam Workers' Party directed its struggle to subdue South Vietnam. The leading military proponent of protracted guerrilla warfare — for the time being — while agreeing to negotiate with the United States was none other than Vo Nguyen Giap, famous for organizing the 1954 defeat of French colonial forces at Dien Bien Phu.
The balance of political forces was decidedly in favor of the militants, who were led by Le Duan, the General Secretary of the Central Committee of the Workers Party of Vietnam. A July 1967 purge of the moderates set the stage for a move to ignite a revolution in South Vietnam by means of a major, conventional offensive.
General Offensive and General Uprising
The North Vietnamese dubbed this initiative General Offensive and General Uprising, but in the United States it would become known as the Tet Offensive. Hanoi believed that the government in Saigon and the U.S. presence in the South were so unpopular that coordinated, large-scale attacks in South Vietnam's major urban centers would spark a popular uprising in the cities, enabling the People's Army of Vietnam and their Viet Cong comrades to sweep in and topple the South Vietnamese government.
This was an enormously ambitious plan; politically because it assumed that the masses in the South would rise up in support for a Communist revolution, and militarily because standing and fighting in urban centers forfeited key advantages that had been taken advantage of until then. In the jungle, Communist forces exploited the element of surprise, choosing opportune moments to engage in combat and slipping away when American forces arrived with overwhelming firepower. In the mountainous South Vietnamese interior, sanctuaries in nearby Cambodia and Laos provided safe havens. In the urban centers of South Vietnam's populous Coastal Region, these advantages were gone.
The Planned Stages of the Tet Offensive
In a preliminary phase, a series of diversionary attacks began in the fall of 1967. These were designed to draw U.S. forces out from the urbanized coastal region to the mountainous border region. The U.S. Marine Combat Base at Khe Sanh in northwestern South Vietnam was besieged as part of this initiative.
Trần Văn Trà was a North Vietnamese general who, at the time of the Tet Offensive, was the chairman of COSVN's Military Affairs Committee. After the unification of Vietnam he authored two articles (included in The Vietnam War: Vietnamese and American Perspectives) in which he described the planned phases of the Tet Offensive as follows: In Phase I, which would begin on January 30, an assault on all of South Vietnam's urban centers would be launched. A simultaneous propaganda offensive would induce South Vietnamese troops to desert their ranks and would call on civilians to rise up against the Saigon government. If total victory was not achieved, follow-up operations were planned to wear down "the enemy" and lead to a negotiated settlement, possibly involving creation of a coalition government and the withdrawal of all U.S. forces. Phase II was scheduled to begin on the 5th of May and Phase III would begin on August 17.