Appendix A
February 13, 1968
Dear Clark:
I have concluded that it would be useful, before you take office, to put before you a certain perspective on aspects of the Vietnam problem. I do so in the belief that these aspects involve critical nuances unlikely to come through clearly in formal briefings or even in supplementary talks. I put them to you with more candor than discretion, believing you would prefer this, but believing in any event that candor and clarity are needed at this juncture of our affairs.
I am concerned with two subjects: (1) the intrinsic value of our bombing in the North; and (2) the relationship of our ground strategy in the South to a pause or cessation of bombing in the North. The bleak events of recent days may have temporarily pushed these subjects into the background, but they will recur, for they are among the central elements of the problem.
Let me acknowledge at the outset several personal premises: first, the idea of a US military victory in Vietnam is a dangerous illusion (primarily because both the Soviets and the Chicoms have the capacity to preclude it—probably by supply operations alone, but if necessary by intervening with their own forces); second, if events in Vietnam are ever to take a turn toward settlement, definitive de-escalation is a prerequisite; and third, admitting all the uncertainty and risk, the most promising approach to negotiations and thus settlement continues to involve a cessation of the US bombing effort against North Vietnam as one of the first steps.
Effectiveness of Bombing the North
When I moved over to the Air Force last October, I asked for the Air Staffs current assessment of the bombing effectiveness. To my surprise, no meaningful assessment existed. Data were in abundance, but they did not constitute a considered assessment. All analytical efforts were going into the bombing operations themselves—that is, how to improve bombing accuracy, how to achieve a higher sortie rate, how to improve electronic measures against stronger NVN air defenses, etc.
I mean to cast no aspersions whatsoever on the professional competence of the Air Staff. In one sense, it is unfair to seek definitive assessment of this kind from the professional operators, for it requires them to examine their own raison d’etre. They come to the problem with a built-in predisposition to avoid the question whether air power can be efficacious in the circumstances where its application has been ordered; their tendency is to assume that it is or can be, and they prefer to concentrate their energies on developing the means and techniques that will prove them right. Such a “can-do” attitude is eminently desirable in executive agents of national policy, but it does have its shortcomings. Subsequently, Secretary Brown ordered the organization of a joint Air Staff–RAND study to examine bombing effectiveness; this is now underway, but it is a laborious effort oriented to a complicated mathematical model. No results at all are expected for several months, and it is my impression that in the end we will get a dusty answer.
On the other hand, an increasing number of experienced analysts outside the ambit of direct operational responsibility have addressed the available facts (including in some cases the intelligence reports and the relevant material from our Embassy and military command); they have come to some firm if depressing conclusions. The most recent, and in some respects the most comprehensive, study was done by the Institute for Defense Analyses. It was commissioned by Secretary McNamara in October and completed in December. While some of its source material is secret, its conclusions are not—and indeed some of them found their way into Secretary McNamara’s final posture statement to the Congress. In summary, these are the conclusions:
• Since the beginning of the air strikes in early 1965, the flow of men and materiel from NVN to SVN has definitely increased.
• The rate of infiltration is not limited by factors in NVN—i.e., available manpower, LOC capabilities, available transport carriers, or available volume of supplies. Rather, the constraints on infiltration relate to the war situation in the South—i.e., the VC infrastructure and distribution system in the South have a limited capacity to absorb and manage additional materiel and troops.
• The bombing has inflicted heavy damage on North Vietnam’s economy and society as a whole ($370 million of measurable damage and the diversion of up to 600,000 people from agriculture to road repair, transport, and air defense). But NVN’s allies have provided economic and military aid substantially in excess of the damage, and the cost of the manpower diversions may be quite small, owing to the considerable slack in NVN’s underemployed agricultural labor force.
• NVN has gone over to decentralized, dispersed and protected modes of producing and handling essential goods and safeguarding the people. It has made a durable adjustment to the bombing.
• The NVN regular army, the VC main forces, and the VC local forces now have better equipment and more effective weapons than in 1965, and the Soviet Union could provide them with even more sophisticated weapons. Only a moderate fraction of the 1.2 million fit males in the prime age groups (17-35) have as yet been inducted into the armed forces.
• On balance, NVN is a stronger military power today than before the bombing began.
Without by any means accepting every point in the IDA analysis, I believe its conclusions are as essentially undeniable as they are unpalatable. Bombing targets in the North did not prevent the current buildup at Khe Sanh, nor notably hinder the recent coordinated VC attacks on the cities. The air war over Hanoi and Haiphong in particular seems increasingly a techno-electronic contest between the US and the Soviet Union with diminishing relevance to the struggle in the South. We seem to have in the bombing campaign an instrument of some modest, but indeterminate, value which plays an essentially psychological role in the struggle and whose most useful service to us may be as a counter to be traded away in a serious bargaining.
This conclusion appears compatible with the San Antonio formula which—if I read it correctly—means that the bombing of the North is something we are prepared to give up while accepting a continuation of the enemy’s “normal” activity, provided that our cessation leads promptly to talks.
The Ground Strategy of Attrition
We are pursuing an aggressive ground strategy of attrition in South Vietnam which often involves US troops fighting search-and-destroy battles in totally uninhabited places, in the worst possible terrain for American forces, at the time of the enemy’s choosing, and with inconclusive results. This is a strategy devised and executed by the Field Commander with remarkably little detailed guidance from either the JCS or higher civilian authority. Certainly the degree of Washington’s critical interest in the way in which the ground war is fought has been in striking contrast to the detailed control which Washington has exercised over the bombing campaign. This strategy generates an increasing rate of US casualties—about 9,500 killed and 20,000 wounded in 1967, as compared to 6,500 killed and 11,000 wounded during the previous seven years.
As indicated by discussion of the bombing, there is only a tenuous military link between our bombing in the North and the casualties we suffer in the South. If we should stop bombing North Vietnam, but continue to pursue the present ground strategy, our casualties are not likely to go down and might go up. But it is doubtful whether a rise would be attributable, in military fact, to a bombing halt. Present US casualty levels are a function of the US ground strategy in the South; they are only distantly related to the bombing.
Yet as we address the prospect of a bombing cessation, it becomes apparent that, however tenuous the military linkage, a political linkage has been allowed to develop. This is usually expressed in some variant of the phrase that a bombing halt would force US troops “to fight with one arm tied behind their backs.” For example, on January 15 the senior Marine officer in Vietnam told the press that “there is a direct relationship between the number of American troops killed and the bombing—there is no argument about that. When the bombing stops, more Americans are killed.”
In my judgment we thus confront a linkage that is in large part a military fiction, but at the same time a palpable political fact. From this I draw the conclusion that, if the President is to accept the consequences of a bombing halt, he must take a corollary decision to alter the ground strategy in ways that will reduce US casualties; otherwise, the domestic political risks may be too high.
One can (I would say parenthetically) make a strong argument that a different ground strategy, less ambitious in purely military terms and more explicitly devoted to protecting the populated areas of South Vietnam, would improve the likelihood of the kind of untidy, unpleasant compromise which looks like being the best available means of our eventual extraction from the morass. It would give us a better chance to develop a definable geographical area of South Vietnamese political and economic stability; and by reducing the intensity of the war tempo, it could materially improve the prospect of our staying the course for an added number of grinding years without rending our own society. But it is not my purpose to advance that kind of argument here.
The point to be made here is simply that, given the political link between bombing in the North and US casualties in the South, an aggressive ground strategy that generates high casualties may prove to be an insuperable obstacle to a bombing halt, even if such a halt is judged by US officials to be in the national interest.
As you know, the President himself has contributed to this linkage on recent occasions—notably in his State of the Union message and in awarding the Medal of Honor to an Air Force officer. ... I do not know what assessment of bombing effectiveness lies behind his words on these occasions, but several key journalists, some of them entirely sympathetic to his dilemmas, believe he is now attributing to the bombing an importance that is seriously at odds with the San Antonio formula. They see a contradiction, but have refrained from pointing it out up to now, out of a concern that this would endanger the San Antonio formula.
If I may summarize:
a. Bombing of the North is making only a marginal military contribution;
b. The San Antonio formula (as clarified by you) recognizes that we can accept the military consequences of a bombing cessation, while the VC continue “normal” hostile actions, provided this leads to prompt talks;
c. Our ground strategy of attrition generates significant US casualties. If the strategy goes unchanged, the casualties are likely to continue and may even rise. But if they rise this will not be properly attributable, as a matter of military fact, to a bombing halt. The casualty levels are primarily a function of the strategy of attrition;
d. Notwithstanding the tenuous military link between US casualties and a bombing halt, it exists as a political fact. Accordingly, if the President decides that a bombing halt is appropriate, it appears that a scaling-down of the ground war would be a necessary corollary decision, in order to make acceptable the domestic political risks of the bombing halt.
I look forward to your coming to the Pentagon, and to working with you on a range of consequential problems in a period of evident storm. You have my abiding respect, and warm wishes for success.
Sincerely
Tim