The Soviets had no intention of putting ICBM's in Cuba. Castro was furious at Krushchev because of this, realizing that the Soviets only wanted to leverage the removal of US nuclear weapons from Turkey and Italy. The idea that JFK drew some imaginary red line in the sand is truly imaginary. The only thing the Americans managed was some superficial PR.
U.S. confirms ISIS computer expert killed in air strike (Reuters)