This month -- October 2012 -- marks the 50th anniversary of the Cuban Missile Crisis. The crisis, which evolved over 13 days, centered on the Soviet Union's placement of nuclear-capable missiles in Cuba, where three years earlier Fidel Castro had staged a successful communist revolution.
The revolution put Cuba in the Soviet sphere of influence; at only 90 miles from Florida, Cuban communism was a dramatic failure of the U.S. policy of containment. As far as the U.S. was concerned, the Cuban-Soviet link was also a violation of the Monroe Doctrine.
But the Cuban-Soviet alliance also created a more urgent situation. It provided the Soviet Union with a base for missiles that could strike not only much of the United States, but Central America and South America as well. The U.S. had pledged to defend Latin American countries in a series of post-World War II alliances; as such the possibility of missiles in Cuba made the U.S. look weak.

The Crisis

On October 14, 1962, an American U2 spy plane took nearly 1,000 photographs showing Soviet missiles, launchers, warheads, and unassembled Soviet bombers in Cuba. Some of the warheads were nuclear. In addition, the Soviets had placed up to 40,000 troops in Cuba.
President John F. Kennedy convened an "executive committee" (EXCOMM) of advisors to help him negotiate the crisis. Chief among them was Kennedy's brother, Robert, who was also U.S. attorney general.
The Kennedys had two obvious choices, neither good: accept Soviet missiles in Cuba or invade Cuba and oust the Soviets. Kennedy was already gun-shy of invasion scenarios, as the CIA-led Bay of Pigs invasion of Cuba had failed in 1961.
Kennedy and EXCOMM crafted a third option. The U.S. declared a blockade around Cuba that would prevent Soviet ships from delivering necessary equipment to ready the missiles. The U.S. would regard any Soviet attempt to break the blockade as an act of war.
A week into the crisis, Kennedy announced the blockade to the public, and he put American military units around the globe on high alert. Soviet ships approached the blockade line, and Americans nervously followed the showdown. Historians regard the second week of the crisis as the closest the world has come to nuclear war.
Meanwhile, Robert Kennedy engaged in covert negotiations with Soviet Ambassador Anatoly Dobrynin. He suggested a deal by which the Soviets publicly remove its missiles from Cuba, and the U.S. would agree to never invade Cuba. Secretly, the U.S. would also remove missiles from Turkey, which were as much a threat to the Soviets as the Cuban missiles were to the U.S.
Soviet Premier Nikita Khrushchev accepted the deal, and the Cuban Missile Crisis ended.

RFK Documents/History Lesson

Coinciding with the 50th anniversary of the crisis, the family of Robert F. Kennedy has released a trove of RFK's documents regarding the incident and his secret diplomacy.
The documents provide a new set of primary sources through which researchers can look at the missile crisis.
Primary sources are the building blocks of history. Like elements or integers in other disciplines, primary sources provide the basis of research and interpretation that inform interpretation for historians, political scientists, and other diplomatic, public policy, and social science experts.
Primary sources tend to be journals, diaries, notebooks, or other records kept by key players in an event or during a given time. (Secondary sources, in case you're wandering, are the books, monographs, or articles that researchers write after consulting primary documents.)
Will the RFK sources reveal anything new about the Cuban Missile Crisis? Hard to tell until researchers comb through them and put their interpretations on them. The crisis has long been regarded as a case study in executive decision making. (Check out Graham T. Allison's and Philip Zelikow's Essence of Decision: Explaining the Cuban Missile Crisis (1999) for a highly regarded examination of the subject.)
You can be sure, however, that the documents will reveal more about the working relationship of the Kennedy brothers, as well as the intricacies of diplomacy during the Cuban Missile Crisis.