The scale of the Soviet deployment went far beyond the CIA’s worst fears. Briefing the president on the afternoon of Saturday, October 20, McNamara estimated Soviet troop strength on Cuba at “six thousand to eight thousand.” CIA analysts arrived at the figure by observing the number of Soviet ships crossing the Atlantic, and figuring out the available deck space. There was one missing element in these calculations: the ability of the Russian soldier to put up with conditions American soldiers would never tolerate. By October 20, more than forty thousand Soviet troops had arrived on Cuba.
