The final declaration of the Geneva Conference on the problems of restoring peace in Indochina was dated 21 July 1954. The second war in Indochina began two years later as the deadline passed for reunification elections and ended on 27 January 1973 as "The Agreement on Ending the War and Restoring Peace in Vietnam" took effect. But the two-year respite that followed the Geneva Conference of 1954 was not to be repeated. What could be called a third Indochina war began immediately after the 1973 agreement.
Although some traces of the Viet Cong (VC) guerrilla forces remained, as well as a few unconvincing contrivances intended to demonstrate the legitimacy of the Provisional Revolutionary Government (PRG) of South Vietnam, the third Indochina conflict quickly assumed the character of conventional war between regular ground forces. Irregulars played an insignificant role in the final outcome. The war's central characteristic was an invasion across well-defined frontiers. With a secure base in the north and a large army already positioned in South Vietnam, the Democratic Republic of Vietnam (DRV) systematically rebuilt and reinforced its expeditionary force without any effective interference until the South Vietnamese ground forces, short of essential resources and demoralized, abandoned entire provinces to concentrate their battered defenders and then collapsed. What follows is the story of that final Indochina struggle and of the eventual and tragic collapse of the South Vietnamese.
The United States in August 1969 entered secret negotiations to end the war in Indochina. Three and a half years later the final agreement was signed in Paris. In a speech to the nation on 25 January 1972 (text in State Dept. Bulletin, 14 Feb. 72.), President Richard M. Nixon made the negotiations public and stressed the urgency the United Stales attached to disengaging from the war and exchanging prisoners of war. The final agreement required major concessions on the part of the Government of the Republic of Vietnam (GVN) and only required the DRV to return prisoners of war and account for soldiers missing in action.
In the final agreement the United States was allowed only 60 days to remove its remaining forces from South Vietnam. On the other hand, the agreement was silent on the presence of North Vietnamese forces in South Vietnam. In a news conference (24 January 1973) announcing the agreement, The Special Assistant to the President for National Security Affairs, Henry A. Kissinger, responded to a related question: "Our estimate of the number of North Vietnamese troops in the South is approximately 145,000 . . . nothing in the agreement establishes the right of North Vietnamese to be in the south . . . The North Vietnamese have never claimed that they have a right to have troops in the South. The North Vietnamese troops in the South should, over a period of time, be subject to considerable reduction" [St Dept Bulletin, 12 Feb 73] Intelligence suggested that Dr. Kissinger's estimate of the strength of the North Vietnamese Army (NVA) in South Vietnam was on the low side. With 13 division headquarters and 75 regiments, the North Vietnamese could have had as many as 160,000 soldiers in the south, an expeditionary force backed up, supplied, and trained from secure bases in the north and in Laos.
No similar advantage accrued to the South Vietnamese. Their logistical and training bases and lines of communication remained vulnerable to infiltration, sabotage, and attack. The South Vietnamese had never been able to carry the attack to North Vietnam, and the agreement provided that "the United States will stop all its military activities against the territory of the Democratic Republic of Vietnam." Although the United States kept forces in Thailand and in the South China Sea and remained capable of either attacking North Vietnam or supporting the South Vietnamese, that proscription in the words of the agreement remained "durable and without limit of time." (Text in State Dept. Bulletin, 12 Feb. 73.)
As time passed, the NVA invasion and attacks grew in boldness and scope without attracting any significant response from the United States. After the final bombing halt following the B-52 raids of Christmas 1972, the North Vietnamese probably never again seriously considered that the United States could be provoked into new reprisals. Even if they had been reluctant to violate the agreement in a brazen manner for fear of American reaction, their inhibitions must have been greatly diminished by the congressional prohibition of 15 August 1973 on further bombing of Cambodia and dissipated entirely during the North Vietnamese conquest of Phuoc Long Province in December 1974. Although conclusive evidence is lacking, the Phuoc Long campaign was probably undertaken, in part at least, to test the American response. Since the United States did not respond, the final offensive could proceed as planned without concern for the high costs that would attend a resumption of American bombing of North Vietnam.
In Article 7, the agreement states that: The two South Vietnamese parties shall not accept the introduction of troops, military advisers, and military personnel including technical military personnel, armaments, munitions, and war material into South Vietnam. The two South Vietnamese parties shall be permitted to make periodic replacement of armaments, munitions and war material which have been destroyed, damaged, worn out or used up after the cease-fire, on the basis of piece-for-piece, of the same characteristics and properties . . . Those restrictions, however, did not apply to military assistance provided North Vietnam by the Soviet bloc and China. Military equipment, supplies, technicians, and advisers continued to flow into Hanoi after the cease-fire. The agreement, moreover, did not specify how the restrictions would be enforced with regard to the NVA forces already in South Vietnam. Responding to a question about this at the news conference of 24 January 1973, Dr. Kissinger said that it was "not in-
conceivable that the agreement will not in all respects be lived up to. In that case, adding another clause that will not be lived up to, specifically requiring it, would not change the situation." That appraisal proved to be an understatement, for the restrictions had no apparent effect on North Vietnam's rebuilding and reinforcing its expeditionary force. On the other hand, American shipments to South Vietnam after the cease-fire were meticulously accounted for as replacements for similar supplies and for equipment lost, used up, or evacuated.
The temporary partition of Vietnam by the Accords of 1954 was continued in the Paris Agreement. That was done, according to Dr. Kissinger (press conference, 24 January), because "the provisions of the agreement with respect to infiltration, with respect to replacement, with respect to any of the military provisions, would have made no sense whatsoever if there was not some demarcation line defining where South Vietnam began." But the true demarcation was 30 kilometers south of the 17th parallel on the Thach Han River where South Vietnamese marines held on to the rubble of Quang Tri City. The North Vietnamese maintained the fiction of the Demilitarized Zone (DMZ) by locating a customs post on the south bank of the Ben Hai River. Meanwhile, the most extensive NVA logistic base in South Vietnam was constructed from the DMZ through Dong Ha and west along Highway 9 to Khe Sanh. Dong Ha became a major port of entry for military supplies, and the traffic across the DMZ soon surpassed anything seen in the years bef ore the cease-fire.
Ever since the North Vietnamese began major military operations against South Vietnam, they used the Ho Chi Minh Trail in southern Laos and eastern Cambodia as their principal logistical corridor. By January 1973 about 70,000 NVA regulars were in Laos, mainly in the logistical corridor, and about 30,000 were in Cambodia. In Dr. Kissinger's words: . . . "there is a flat prohibition against the use of base areas in Laos and Cambodia. There is a flat prohibition against the use of Laos and Cambodia for infiltration into Vietnam . . . there is a requirement that all foreign troops be withdrawn from Laos and Cambodia, and it is clearly understood that North Vietnamese troops are considered foreign with respect to Laos and Cambodia. It is our firm expectation that within a short period of time there will be a formal cease-fire in Laos which in turn will lead to a withdrawal of all foreign forces from Laos and, of course, to the end of the use of Laos as a corridor of infiltration. [Press Conference of 24 Jan, State Dept Bulletin, 12 Feb 73] That withdrawal failed to materialize. There was little reason to think that it would, considering the entrenched position of the North Vietnamese in southern Laos, their reliance on the logistical network established there, and their record of violating the agreements of 1954 and 1962. In the two years after the 1973 cease-fire, the NVA shifted sizeable logistical units from Laos into South Vietnam as it developed the Route 14 corridor south from Khe Sanh. It also moved its 968th Infantry Division from Laos into the Kontum-Pleiku area. But it did not stop using the corridor. On the contrary, it built macadam roads and added concrete culverts and bridges, and infiltration continued. During 1973 over 75,000 replacements entered South Vietnam, mostly through Laos. South Vietnam lacked the means to cope with that flagrant breach of the agreement, and although the United States was concerned, U.S. reconnaissance over the corridor was greatly reduced and what remained did not reveal the destination of some major NVA reinforcements moving south in late 1974 and early 1975.
Another important provision in the agreement established an International Commission of Control and Supervision (ICCS). The ICCS was supposed to detect and investigate violations, control entry into South Vietnam, and generally supervise the ceasefire. Unfortunately for South Vietnam, two of the four members of the commission, Poland and Hungary, were not impartial. They did not man the entry points into South Vietnam, except those used by the United States, and failed to inhibit in any way the movement of men, supplies, and weapons from North Vietnam. One member, Canada, quickly became disenchanted with the frustrations of dealing with an uncontrollable situation and resigned. Replacing Canada, Iran experienced the same frustrations but persisted in trying to give some balance to the reporting and some meaning to the cease-fire. In the face of the North Vietnamese invasion, however, and opposed at every turn by the decidedly hostile Poles and Hungarians, the other commission members could not have changed the outcome of the conflict, no matter how dedicated they were to fairness, law, and peace.
Domestic politics forced the United States to observe the agreement even while the North Vietnamese blatantly violated it. Domestic policies also prevented adequate U.S. support in arms, ammunition, and equipment. Thus the military balance shifted in favor of the invader as the capabilities of the South Vietnamese armed forces declined until they were unable to withstand the final NVA offensive.