The Cuban Missile Crisis arose from escalating tensions between the US and USSR following the Cuban Revolution. In October 1962, US reconnaissance flights discovered Soviet nuclear missile sites being constructed in Cuba. President Kennedy implemented a naval blockade of Cuba and demanded the Soviets remove the missiles. After several days of negotiations, Soviet Premier Khrushchev agreed to remove the missiles in exchange for a pledge from the US not to invade Cuba and to remove its missiles from Turkey. The crisis highlighted the dangers of the Cold War and nearly resulted in nuclear war between the two superpowers.