First of all, seeing as to how more than one SE user has
questioned the seriousness of the Cuban missile crisis, let me
try to outline how tense things were at the time. - The Cuban
missile crisis is the only time ever that any section of the US
military has mobilised to DEFCON 2. The erstwhile SAC was at
DEFCON 2 while the rest of the armed forces were at DEFCON 3.
Kennedy had informed his military advisers (who were champing at
the bit to invade Cuba and depose Castro) that if any of the
recon flights were attacked, that he would authorise (a planned)
invasion of Cuba. Kennedy eventually preferred to "quarantine"
the island instead even after a U-2 was shot down. Also, Kennedy
had explicitly promised the American people less than a month
before the crisis that "if Cuba should possess a capacity to
carry out offensive actions against the United States...the
United States would act." The Soviet commanders in control of
the nukes on Cuba were authorised to launch if the US ever
invaded Cuba. Castro himself adv