areas in which the Soviets were (inaccurately) perceived as leading the United States, while heated Soviet rhetoric added to political pressure. The 1960 U-2 incident, involving Francis Gary Powers, as well as the Berlin Crisis, along with the test of the Tsar Bomba, escalated tensions still further. Cuban Missile Crisis This escalating situation came to a head with the Cuban Missile Crisis of 1962. The arrival of Soviet missiles in Cuba was conducted by the Soviets on the rationale that the US already had nuclear missiles stationed in Turkey, as well as the desire by Fidel Castro to increase his power, his freedom of action, and to protect his government from US-initiated prejudicial resolution of ideological disputes through the use of military force, such as had been attempted during the Bay of Pigs Invasion in April 1961. During the crisis, Fidel Castro wrote Khrushchev a letter about the prospect that the "imperialists" would be "extremely dangerous" if they responded militarily to the Soviet stationing of nuclear missiles aimed at US territory, less than 90 miles away in Cuba. The following quotation from the letter suggests that Castro was calling for a Soviet first strike against the US if it responded militarily to the placement of nuclear missiles aimed at the US in Cuba: If the second variant takes place and the imperialists invade Cuba with the aim of occupying it, the dangers of their aggressive policy are so great that after such an invasion the Soviet Union must never allow circumstances in which the imperialists could carry out a nuclear first strike against it. I tell you this because I believe that the imperialists' aggressiveness makes them extremely dangerous, and that if they manage to carry out an invasion of Cuba—a brutal act in violation of universal and moral law—then that would be the moment to eliminate this danger forever, in an act of the most legitimate self-defense. However harsh and terrible the solution, there would be no other. The Cuban Missile Crisis resulted in Nikita Khrushchev publicly agreeing to remove the missiles from Cuba, while John F. Kennedy secretly agreed to remove his country's missiles from Turkey. Both sides in the Cold War realized how close they came to nuclear war over Cuba, and decided to seek a reduction of tensions, resulting in US-Soviet détente for most of the 1960s and 1970s. Nonetheless, this reduction of tensions only applied