54. Memorandum From the Acting Chairman of the Board of National Estimates (Smith) to Director of Central Intelligence McCone0

SUBJECT

  • Soviet Challenge to the Quarantine1
1.
Our best guess is that:
a.
A challenge at sea to the quarantine is unlikely, at least for a day or two.
b.
Thereafter a challenge is likely if the Soviets believe that their political efforts are not succeeding and a heightening of the crisis is required.
c.
In staging any challenge, they would probably employ a vessel with nonmilitary cargo, refuse boarding, and exploit the subsequent attack by the US.
d.
Retaliatory actions would follow if the incident itself failed to produce quick political results. It would be aimed either at a US ship elsewhere or at access to Berlin; we think the latter somewhat more likely.
2.
Today’s TASS statement suggests that the Soviets wish to retain full freedom of action while they consider their initial moves. There is some intelligence, dating from before the President’s speech, indicating that the Soviets had decided to run any US blockade which might be established. Nevertheless, we think it likely that, at least for a day or two, they will avoid a challenge at sea while they observe the results of their political efforts to get the quarantine lifted.
3.
If the USSR feels that these efforts are succeeding, the Soviets will probably continue to avoid challenges, lest an incident interrupt this favorable trend. On the other hand, if Soviet political tactics are bearing little fruit, they may judge that an incident would be useful as a means of heightening the crisis further and bringing extra international pressure on the US.
4.
If and when they decide to permit an incident of this sort, the Soviets would not allow the US to board a vessel, since this would mean acceptance in principle of quarantine. Instead, their tactics would probably be to choose a ship carrying a nonmilitary cargo and to allow it to be attacked.
5.
It is possible that the Soviets, in deciding to test the quarantine, would accompany their probe ship with a submarine which would counterattack the US vessel after the Soviet ship was struck. Or the counterattack might be made by an aircraft from Cuba. We think this unlikely, however, because the Soviets would almost certainly estimate that the US would respond by tightening the blockade and launching a full-scale effort to seek out and destroy a Soviet submarine in the area of quarantine operations.
6.
After an incident, the Soviets would probably allow a pause while they exploited this incident and observed its effects. Unless the US showed signs of quickly yielding, however, we believe that they would then follow with some form of retaliation.
7.
We do not believe that this would take the form of major military action. Instead, the Soviets would choose between an attack on a US ship elsewhere or a move on the access routes to Berlin, designed to remind the US of the vulnerability of its position there. In most circumstances, they probably would regard a Berlin move as both more effective and easier to control. Still, they would probably exercise care to avoid giving the impression that they were moving toward a general showdown with the US.
8.
The USSR might use a submarine, however, to deliver through the quarantine some particularly critical item and to demonstrate, with a subsequent announcement, its ability to frustrate US efforts.
For the Board of National Estimates:
Abbot Smith
  1. Source: Department of State, S/S Files: Lot 65 D 438, CIA-Cuba. Top Secret. The source text bears no drafting information.
  2. Another memorandum from Smith to McCone, October 23, estimating the effect on Cuba of a blockade covering all goods except food and medicines is in the Supplement. (Kennedy Library, National Security Files, Countries Series, Cuba, Subjects, Intelligence Materials, 10/1/62-11/12/62)