345. Memorandum From the President’s Special Assistant (Rostow) to President Johnson1

Mr. President:

Herewith, the CIA analysis of the air campaign against lines of communication2—which I held up so you would have along with it my own view of how the problem should be posed.

In a subsequent talk with Bob McNamara, I further narrowed our differences.

As you can see from what follows, the way I put the case at the meeting yesterday is wholly consistent with the evidence of the report. The problem is that the analysis in the report is split into two arguments which are never coherently related:

We have not and cannot reduce capacity so they can’t get men and supplies through to the South.
Very extensive consequences flow from our bombing of the North.

That split in analysis is why men like Dick Helms accept the report but oppose cessation of bombing. I hope that what follows is a basis for reconciling and unifying judgments within the government.

As indicated in the attached more detailed comments, the bombing campaign has achieved the following:

  • —At little cost in civilian casualties and at acceptable costs in our loss rates, the bombing has severely curtailed North Vietnam’s industrial and agricultural production.
  • —Therefore, there has been a radical increase in North Vietnam’s requirement for foreign aid in order to sustain her war effort and to sustain her economy at minimum levels (imports up from 2,100 metric tons per day in 1965 to 4,300 in 1967; Soviet aid up from $100 million to $700 million annually).
  • —It has required the diversion of up to 600,000 workers to defend against or counter the effects of the bombing.
  • —It has increased substantially the number of men and tons which must be dispatched from the North to get one man or one ton into South Vietnam. We don’t know just how much but we do know that [Page 856] it has (1) caused them to resort to the shorter routes across the DMZ and (2) contributed to their abandoning large-scale operations within South Vietnam.

Although I have some personal reservations on whether the North Vietnamese could, if they wished, do as much more as the analysis indicates, I basically agree that bombing cannot reduce their capacity to support the South to the extent that they would be forced to abandon the war in the South.

There remain two significant, but unanswerable, questions:

  • —Is the present level of communist effort in the South what they consider their optimum strategy or is it the best they can or are willing to mount in the face of the bombing?
  • —What would they do if we stopped bombing?

Although we can’t predict what the North Vietnamese would do, we can say that:

  • —They would be able to put men and supplies into the South at lower cost.
  • —The resources available to them would be increased, which would enable them to put more into the South or make life in the North easier, or both.
  • —It would be a lot easier for them to sweat out the war.

  1. Source: Johnson Library, National Security File, Files of Walt Rostow, Bombing. Top Secret. The notation “L” on the memorandum indicates that the President saw it.
  2. Not printed; it is an intelligence memorandum entitled “Rolling Thunder: The 1967 Campaign Against the LOC’s,” undated, which concluded: “Transport operations have been seriously disrupted, losses of transport equipment have increased sharply, and the costs and difficulties of maintaining traffic movements have multiplied. But as a result of countermeasures, the use of alternate routes, and foreign assistance, North Vietnam’s logistic capabilities have not been reduced, and there is convincing evidence that the military and economic goods needed to support the war have continued to move.” Another copy is ibid., Country File, Vietnam, 3H(2) Appraisal of Bombing.