218. Telegram From the Embassy in Vietnam to the Department of State1

3120. Embtel 3003.2 Subj: Future requirements for US military manpower in SVN. The authorized US military strength in SVN is presently about 28,000. As individuals or as members of units, these men are providing the RVNAF with advice, air support, and logistic support or are reinforcing the security of selected military installations. MACV is recommending a further increase of about 18,000 US personnel to round out table of organization shortages, to improve local security at US billets and installations, to provide better air and communications support, and to create a much needed logistics command. Furthermore, MACV is recommending the introduction of the remainder of the 9th MEB to give greater strength to the security forces of the Danang-Phu Bai area. If all of these recommendations are approved, we are headed for a US military strength in SVN of approximately 50,000.

In addition to these mounting requirements, there is a more significant one taking form which is discussed in Embtel 3003. It is quite clear that the existing operational units of the armed forces of Vietnam are insufficient to cope effectively with the internal Viet Cong threat. In [Page 487] recent weeks, we have seen a serious deterioration in the I and II Corps which has required the transfer of most of the RVNAF general reserve units to that area. Although there is an intensified build-up of ARVN forces in process, the full effect of this expanded mobilization will not be felt in terms of available operational units until toward the end of calendar 1965. Thus, we are faced with an immediate shortage of trained military and paramilitary units to offset the mounting strength of the Viet Cong. The basic question is whether we can accept this manpower shortage over the coming months and await the readiness of the new ARVN units, or whether some way must be found at once to compensate for the shortage during the intervening period.

Before attempting to answer this question, it is first necessary to decide what kind of strategy should be pursued during calendar year 1965. Strategy A might be to accept the present unsatisfactory progress in defeating the Viet Cong and base our hopes on the effect of the pressure of the current air attacks on Hanoi. Even if we make little progress in pacification during the coming months or even accept further retardation, this delay will be inconsequential if, in the end, Hanoi throws in the sponge and agrees to cease aid to the Viet Cong and to cooperate in their liquidation.

Strategy B might be to take the position that it is essential to reverse the downward trend in certain critical provinces, not only to avoid the danger of a debacle in these areas but also, through in-country successes, to give added weight to the effectiveness of the air campaign on the will of Hanoi. If the latter is losing both in SVN and suffering from repeated air attacks in NVN, this condition should accelerate the decision of the North Vietnamese leaders to mend their ways.

Strategy C might be to take the position that we must do everything possible to speed up the in-country campaign against the Viet Cong to prevent a possible collapse of national morale and to shorten the period of international tension which will exist throughout the duration of our military pressures on Hanoi. This means go for broke to win rapidly. To accept such a strategy is to support the need for the injection of all possible military strength into SVN which can be supported and be used effectively.

Without choosing between these three strategies at this point, let us assume that we are headed along the course of either Strategy B or C. Furthermore, let us make the assumption which I believe is correct that no introduction of US forces less than about 9–12 battalions will have any significant effect on the military situation in this country in the short term. So the immediate question is how to employ such a force if the decision is taken to introduce it.

In extension of the discussion on the same subject in Embtel 3003, I would say that such a US force could be used in three ways: (1) in a defensive [Page 488] or offensive enclave, (2) in territorial clear-and-hold operations or (3) as mobile reaction reserves. The defensive enclave is typified by the present employment of the two battalions of Marines in defense of the Danang airbase. They secure the immediate airbase but do not engage in military operations outside the defensive perimeter. This disposition could be changed into an offensive enclave if the Marines were allowed to sally forth and engage in operations either initiated by themselves or in support of operations conducted by ARVN. In any case, they would remain responsible for the security of Danang.

The use of US forces in territorial clear-and-hold operations amounts to giving them a mobile offensive role similar to that of the ARVN regular units. The plateau region in west central Vietnam has often been cited as a suitable region for this kind of employment. The advantages of this region and this mission are discussed in Embtel 3003.

The mobile reaction use amounts to assigning a mission to the US forces tantamount to that of the general reserve battalions of ARVN. Under this concept, the US forces would not go forth to find and fix the enemy but would wait until ARVN had found and fixed him, then as a striking force in reserve, they would enter action to finish the enemy who had been previously fixed by indigenous forces.

These three modes of employment all have their pros and cons. The enclave concept assures the security of an important installation or installations with minimum exposure of US personnel to casualties. It places our forces in locations on or near the coast where egress and ingress are easy to assure. However, if only a passive defensive role is assigned to them, they will have little effect upon the war against the Viet Cong and little influence in relieving ARVN forces for employment elsewhere. If the enclave is used offensively, the latter objection does not apply but, on the other hand, the exposure of US personnel to losses is increased.

The territorial clear-and-hold mission could have a significant effect in assisting the campaign against the Viet Cong—if successfully implemented. However, it runs into all of the longstanding objections to the use of US forces in anti-guerrilla operations in SE Asia. Our forces would inevitably suffer serious losses and at the outset would probably not do too well in operations in strange terrain for which they have not been specifically and intensively trained. There would be the inevitable problems of the identification of the enemy and of command relations with the ARVN and with the pacification representatives of the GVN ministries. There would be many legal questions raised relating to detention and arrest of Vietnamese citizens and to use and damage of Vietnamese property. There would be the difficulty of acquiring intelligence in a country where both the language and the environment are unfamiliar. Our forces would be operating under conditions in which the avoidance [Page 489] of ambush has never been solved by GVN forces operating for years in this environment; hence we would have to assume that the newly arrived US forces would have even greater difficulties in finding and fixing the enemy and in protecting themselves against surprise.

The use of our forces in a mobile reaction role has many advantages. To some extent, it minimizes the problem of finding and fixing the enemy. It assures that their employment would be in the climax of an important engagement where a significant element of the enemy could be destroyed. It would allow our forces to have their permanent stations more or less isolated from contacts with the local population in coastal areas easily supplied and supported by air and sea. In such locations, they would also avoid involvement [in] pacification operations which can only be carried out by representatives of the GVN. With air mobility, the employment in central reserve would allow the use of US forces over wide areas of the country and would assure a maximum return from the commitment of our manpower. This mode of employment would also give MACV an additional lever to influence tactical operations since the employment of our battalions could be made conditional upon the concurrence of the US advisors in the tactical plans of the ARVN commanders.

There are no particular disadvantages to the mobile reaction concept except the hard fact that we will take losses whenever our troops are plunged into the midst of an engagement in progress. Also they will necessarily be closely associated in action with ARVN and hence will have to work out appropriate command relationships for each operation.

It should be noted that there is nothing incompatible between a combination of the first and third concepts, that is, of placing US units in mobile reserve for reaction which would operate out of offensive enclaves. One could establish perhaps three such enclaves on or near the coast, each garrisoned by a brigade of three battalions. Under normal conditions, at least two of these battalions could be used on reaction operations leaving the third on the security mission. If the third battalion were required outside the enclave, it would be possible to reinforce the enclave either from another enclave or from a Marine or airborne unit brought in from the Fleet or from Okinawa. A first step toward effecting this disposition could be to organize the Marines in the Danang area into the first of these offensive enclaves. Thereafter, we could bring two Army brigades into areas such as Qui Nhon, Nha Trang and Vung Tau-Bien Hoa. This could be an initial disposition capable of expansion after acquiring experience and gaining evidence as to the effectiveness of US forces in this new role. This conservative beginning would give us insight into the political and psychological effect of US combat participation on the GVN, on the armed forces of Vietnam and on the people.

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With regard to the popular reaction, it is far from clear what the attitude of the GVN and the Vietnamese people would be toward the introduction of these forces. It could be that Vietnamese morale would be raised and their will to fight enhanced by the presence of US forces and their participation in combat on the ground. It is equally possible that the presence of these additional Americans would tend to sap the already flaccid purpose of the Vietnamese and would promote an attitude of “let the US do it”. In any case, before introducing further US reinforcements into SVN it is essential to be sure that they will be enthusiastically welcomed by the government, by the armed forces and by the people.

Thus, we need an answer to the following questions before proceeding farther. (A) What strategy does the US propose to follow calendar year 1965? (B) To carry out that strategy, is it necessary to bring in additional US ground forces? (C) What will be the reaction of the Government and people of Vietnam to this proposal? If the answers to these proposals support the introduction of additional US ground forces, I would then favor their employment, initially at least, in accordance with the offensive enclave-mobile reaction concept.

  1. Source: Department of State, Central Files, POL 27 VIET S. Top Secret; Priority; Exdis. Repeated to DOD, the White House, CIA, and CINCPAC. Received in the Department of State at 9:24 a.m.
  2. Document 204.