McGeorge Bundy was National Security Advisor to two presidents, John F. Kennedy and Lyndon Johnson. He was a strong advocate of increased US military involvement in Vietnam, as well as direct action against North Vietnam. This memo from Bundy to President Johnson was dated February 7th 1965:

“We believe that the best available way of increasing our chance of success in Vietnam is the development and execution of a policy of sustained reprisal against North Vietnam, a policy in which air and naval action against the North is justified by and related to the whole Viet Cong campaign of violence and terror in the South.

While we believe that the risks of such a policy are acceptable, we emphasise that its costs are real. It implies significant US air losses, even if no full air war is joined, and it seems likely that it would eventually require an extensive and costly effort against the whole air defence system of North Vietnam. US casualties would be higher and more visible to American feelings than those sustained in the struggle of South Vietnam…

Once a program of reprisals is clearly underway, it should not be necessary to connect each specific act against North Vietnam to a particular outrage in the South. It should be possible, for example, to publish weekly lists of outrages in the South and to have it clearly understood that these outrages are the cause of such action against the North as may be occurring …

We must keep it clear at every stage both to Hanoi and to the world, that our reprisals will be reduced or stopped when outrages in the South are reduced or stopped and that we are not attempting to destroy or conquer North Vietnam…

We think it plausible that effective and sustained reprisals, even in a low key, would have a sustained depressing effect upon the morale of Viet Cong cadres in South Vietnam. This is the strong opinion of CIA [within] Saigon. It is based upon reliable reports of the initial Viet Cong reaction to the Gulf of Tonkin episode, and also upon the solid general assessment that the determination of Hanoi and the apparent timidity of the mighty United States are both major items in Viet Cong confidence…

We cannot assert that a policy of sustained reprisal will succeed in changing the course of the contest in Vietnam. It may fail, and we cannot estimate the odds of success with any accuracy; they may be somewhere between 25% and 75%. What we can say is that even if it fails, the policy will be worth it. At a minimum it will damp down the charge that we did not do all that we could have done, and this charge will be important in many countries, including our own.”