430. Memorandum From the Deputy Director of the Central Intelligence Agency (Cline) to the Director of Central Intelligence (McCone)1

SUBJECT

  • Vietnam
1.
Out of the fog of medieval scholasticism surrounding many months of discussion of Vietnam, a few simple propositions seem to me to emerge as true. Most of the other subtle distinctions and arguments I have heard do not seem to me to affect the US course of action.
2.
The political and military situation in SVN is bad. It may deteriorate rapidly at any time. Enlightened and imaginative efforts to stabilize SVN and defeat the VC by actions in SVN should be made whatever course of action the US adopts. The odds are these efforts will not succeed in reversing the unfavorable trend in SVN certainly not for a very long time, during which the US position and the stability of SVN would remain liable to sudden collapse.
3.
In this unfavorable position, the US can take military action against NVN designed to achieve the limited objectives of causing the cessation of NVN support (cadres and supplies) and direction of VC insurgency in SVN. Even if successful, this action would not in and of itself insure achievement of the US basic strategic objective of maintaining a stable and effective non-Communist SVN, which is a valid and essential requirement of US policy in Southeast Asia and worldwide. It probably would buy time to try to improve the security situation in SVN, to gradually contain and eventually destroy the VC as an effective insurgent force, and to establish a stable, friendly government.
4.
The way achievement of this limited objective of cutting off support and direction from NVN would operate on the situation in SVN would be: (a) reducing VC strength and military capability; (b) damaging VC morale by making the prospect of early victory remote; and (c) greatly increasing SVN morale by demonstrating US commitment to our basic strategic objective in Southeast Asia and eliminating the infiltration problem which makes counterinsurgency efforts seem hopeless.
5.
The first phase in any military course of action aimed at causing the cessation of NVN support and direction of the VC insurgency ought to center on US air interdiction of infiltration lines of communication and US air strikes against infiltration associated facilities in Laos and inside NVN near the borders of Laos and the DMZ.
6.
The likelihood of extreme NVN or Chicom military reactions against such US military action would be small. There would be an intensive world-wide Communist political and propaganda campaign against the US. NVN would certainly try to defend its territory and forces, and there is likely to be a vigorous NVN effort at reprisals against US/SVN forces and facilities within reach.
7.
There is a chance, though less than an even chance, that NVN would calculate that more damaging US attacks would follow. In that case, NVN might effect a cessation or a marked reduction of insurgent activity in SVN and its support and direction thereof, hoping to negotiate with the US terms that would not call for inspection and control arrangements adequate to prevent resumption of its support and direction at a later date. This would be a gain for the US provided the US insisted on adequate inspection and control and did not commit itself not to make further air strikes if NVN support and direction of the VC insurgency in fact continued. It would be a helpful psychological factor working toward a reversal of the unfavorable trend in SVN, and it might be the decisive one in achieving such a reversal.
8.
There is, of course, a chance, though small, that NVN would react extremely with a frontal military assault or that the Chicoms would intervene directly on a large scale with air units and/or ground combat units. The US would have to be prepared to deal with these eventualities, but should not be deterred from military action by the risk. If, in fact, on grounds that seem irrational and reckless to us, NVN with Chicom support responds in this way, there would in fact be no way to avoid a direct military conflict between the US and NVN short of acquiescence in Communist domination of SVN and the abandonment of US objectives in Southeast Asia which we have agreed are valid and essential.
9.
If NVN temporizes and makes no move toward cessation of its support and direction of VC insurgency in the face of the first phase US military actions described above, as is most likely, the US should proceed, after a pause, to a second phase which would extend air attacks to infiltration associated targets deeper within NVN, and in deliberate sequence to a third phase involving blockade (“quarantine”) of NVN. It is impossible to estimate with confidence the situation that would exist in these successive phases in either NVN or SVN, and therefore impossible to estimate with confidence the relative likelihood [Page 964] of the various possible Communist reactions that might occur. The range of possibilities would be the same, however, and the consequences the same
10.
Generally, it is clear that the chances would increase at each step of increased pressure on NVN that NVN would opt to negotiate a cessation of support and direction of the VC insurgency on the most favorable terms they could achieve. At each step the US bargaining position would improve. At each step the chances of extreme NVN and Chicom reaction would increase. Even at the extreme range of US military actions aimed at bringing pressure on NVN, however, provided they do not progress to the point of occupation of NVN territory by substantial numbers of US ground forces, the Chicoms will be reluctant to become directly involved in a military conflict with the US and the chances are therefore better than even that they would not introduce large-scale ground combat units into Vietnam or Laos. As a consequence, the chances are also better than even that NVN would not itself directly invade SVN or Laos but would instead intensify its efforts to negotiate on the best terms possible.
Ray S. Cline
  1. Source: Johnson Library, National Security File. Vietnam Country File. Vol. XXII. Memos. Top Secret.