The history of major international crises and incidents tends to develop over time – there’s the ‘official’ history as recorded through newpapers and interviews with politicians and then there’s the hidden history. The latter only begins to appear as participants in the original events die and previously secret documents are declassified.
In this case, it seems that the Intermediate Range Ballistic Missiles (IRBMs) spotted from the air were only part of the picture. When the crisis first blew up, US Secretary of Defense Robert McNamara suggested that 40 odd missiles in Cuba represented litttle or no military threat to America. The US had around 5,000 strategic warheads at the time – compared to a Soviet total of 300. McNamara argued that 340 wasn’t exactly going to tip the balance of power. Kennedy disagreed. Sure, there wasn’t much strategic threat represented here – but the political threat was huge. Russian nuclear missiles in a communist country ninety odd miles from the Florida coast was unacceptable – end of. Had Kennedy known that as well as the IRBMs, Khrushchev had also sent Castro 100 tactical nukes (100-200 kiloton range) he would have been even more determined to take action. Possibly it’s just as well he didn’t…
Since Kennedy had been waxing lyrical about the IRBMs it seems Khrushchev thought it superfluous to mention the existence of the tac-nukes to him and as a result they were not included in the deal that brougt the official crisis to an end. However, Khrushchev was understandably anxious to ensure that his deal with Kennedy did no permanent damage to Soviet/Cuban relations. After all, an island full of fraternal communist brothers and sisters so close to the USA could prove useful.
With Castro and the Cuban government going ballistic about having been let down by their so-called allies, Khrushchev bethought him of the 100 tac-nukes. Perhaps if he made a gift of them to the Cubans Castro could be put back in his box… Accordingly, Khrushchev dispatched his First Deputy Premier Anastas Mikoyan to Cuba to finalise the deal.
At this point the Cuban crisis could well have flared up again. Arriving in Havana, Mikoyan was shocked by Castro’s state of mind. He described the Cuban leader as given to violent mood swings and sudden savage fits of temper as he railed at Mikoyan about how Russia had abandoned them. Mikoyan had a good long think about whether or not this was the sort of guy who should be trusted with 100 nukes (each one about 20 times more powerful than the Hiroshima bomb) and seems to have decided this was a bit of a no-brainer.
In a superb piece of political finesse, he persuaded Castro that giving him the nukes would in fact violate a Soviet law on the proliferation and sale of nuclear weapons. No such law existed, but Castro wasn’t to know that. The Cuban leader gave in to the seemingly inevitable and the nukes were crated up and returned to the Soviet Union by the end of the year. Just as well really that Comrade First Deputy Premier Mikoyan was thinking on his feet.