Fifty years ago this month, the United States and Soviet Union faced off in what is commonly considered the most dangerous crisis of the Cold War and, given the catastrophic consequences of a thermonuclear exchange, perhaps the most frightening military confrontation in human history.

In October 1962, the United States discovered that the Soviet Union was deploying in Cuba medium-range missiles armed with nuclear weapons that could hit much of the continental United States, after President John F. Kennedy had vowed never to allow such an act and the Soviets denied they would ever do such a thing. Kennedy and his advisers undertook almost two weeks of intense analysis, debate and back-channel diplomacy, employing a naval quarantine and crafting a complex deal that led the Soviets to remove the missiles (and other military forces) in exchange for an American guarantee not to invade Cuba and a secret promise to remove its nuclear-tipped missiles from Turkey.

There have already been and will continue to be numerous workshops, analyses and articles conveying “lessons” from this signal historical event. What should a nonexpert make of these accounts? Aficionados of the crisis still debate scores of smaller details that likely appear confusing and obscure to most outsiders. And despite countless books, articles and reams of declassified documents, the origins, resolution and consequences of the crisis remain both contentious and murky. Yet while there is little consensus on the answers and much scholarly work still to be done, it is possible to at least identify three key questions that should frame any discussion of the Cuban Missile Crisis.

A Bold Move

First, why did the Soviet Union decide to put missiles in Cuba in 1962? Why did the Soviet leader Nikita Khrushchev undertake such a bold and risky gambit, and what did he hope to accomplish? There are at least three competing explanations:

Protect Cuba and its revolution: Some scholars who have looked at the Soviet documents have noted the almost romantic attachment Russian leaders had to the revolution in Cuba. Cuba was the first communist country in the Western Hemisphere, constantly threatened by its superpower neighbor ninety miles to the north. The Soviets not only wanted to protect the charismatic Fidel Castro and his regime but also needed to burnish their waning revolutionary credentials in the face of challenges from Mao’s People’s Republic of China.

Improve the Strategic Nuclear Balance: In the late 1950s, particularly after the launch of Sputnik, many American analysts feared that the Soviet Union was gaining a significant and threatening lead over the United States in nuclear capabilities. Improved U.S. intelligence capabilities, particularly the aerial photographs produced by the Corona satellites, revealed there was a large gap—but one that favored the United States. In October 1961, Deputy Secretary of Defense Roswell Gilpatric gave a speech laying out America’s great advantages in its ability to target the Soviet homeland with strategic nuclear weapons, a ploy that may have embarrassed Premier Khrushchev and increased his desire to catch up to and cancel out America’s nuclear lead as quickly as possible.

A Maneuver to Resolve Larger Issues: Several important geopolitical issues in Central Europe resulting from the Second World War had not been resolved when the crisis began in October 1962. The Soviets were especially perturbed by the unsettled status of West Berlin, located in East German territory, affiliated with a politically open and economically booming West Germany, defended by NATO and occupied by British, French and U.S. troops. In late 1958 and again in 1961, Khrushchev issued ultimatums demanding a resolution of West Berlin’s status that would have forced a removal of these troops. The historian Marc Trachtenberg has persuasively argued that the Soviet’s real worry, however, was West German interest and increased access to nuclear weapons, which the Soviets understandably saw as a grave threat to their interests.

The Withdrawal

Why did the Soviets remove the missiles from Cuba? There are several arguments for what factors were decisive in resolving the crisis without a war:

The Balance of Conventional Forces: Many of the key American decision makers involved in the crisis—Secretary of Defense of Robert McNamara and National Security Advisor McGeorge Bundy, for example—believed the nuclear balance was irrelevant and that the crisis ended on terms favorable to the United States because of its overwhelming conventional superiority over the Soviets in the Caribbean. The evidence, however, is mixed. Why didn’t a similar if not larger Soviet conventional balance around Berlin allow it to prevail against the United States during the previous four years? Furthermore, many of the arguments made about the conventional balance and the Cuban Missile Crisis were made during contentious debates over controversial U.S. nuclear policies during the Reagan presidency.

The Balance of Strategic Nuclear Forces: One of the most controversial issues from the crisis is calculating what the precise balance of strategic nuclear forces actually was and what role this imbalance played in determining the outcome. There is little doubt that the United States possessed an overwhelming superiority in deliverable strategic nuclear capability, as much as seventeen to one in some estimates. To what extent did this superiority matter? Many scholars have argued it is impossible to translate nuclear superiority into effective coercive power, while others have argued the opposite. For the Cuban Missile Crisis, this question turns on whether both sides in the crisis believed the United States could have launched a first strike that would have destroyed the Soviets’ ability to respond in kind—the so-called splendid first strike—and whether these perceptions influenced each side’s behavior during the crisis.

The Balance of Resolve: In a non-nuclear world, the credibility of threats often turned on calculations of the balance of conventional military power between adversaries. A threat made by a country with more tanks, battleships and troops than its adversary often carried more weight, and was more likely to be successful, than threats from states that lacked military superiority. In the nuclear age, however, there is little agreement on whether and how nuclear threats work, regardless of the balance of forces. In a world where any nuclear use may be irrational, might the side with the greatest willingness to take risks prevail?

The Fallout

What were the consequences and larger meaning of the crisis?

The origins of détente: 1962 was an extraordinarily dangerous year. 1963, however, saw a dramatic decrease in tensions and the beginnings of what we might call détente between the superpowers. While there were dangers to be sure—the Cold War rivalry heated up considerably in the late 1970s and early 1980s—never again was the danger of thermonuclear war so imminent. The crisis ended peacefully, tensions over Berlin abated and negotiations commenced for a limited test-ban treaty. Was this cooling of tensions simply a response to coming so close to and ultimately averting catastrophe? Or were the fundamental clash of interests that drove the crisis in the first place somehow resolved? While U.S.-Soviet relations improved, America’s relations with key NATO partners such as France, Great Britain and West Germany became, in different ways and at different levels, more turbulent and strained. What was the connection?

The origins of a quagmire: Many scholars have pointed to the deliberations of Kennedy’s executive committee during the “thirteen days” as a model for managing complex, dangerous crises. A less useful consequence of the executive-committee process may have been a misplaced faith by American policy makers in their ability to control and dictate crises, send effective signals and calibrate escalation, lessons that many believe led to some of the tragic mistakes behind the military escalation in Southeast Asia. Did the wrong lessons learned by the decision makers in Camelot bring the disaster of the Vietnam War?

The Role of Nuclear Weapons

As policy makers debate the consequences of how to prevent Iran from acquiring nuclear weapons, understanding the history of the Cuban Missile Crisis may be more valuable than ever. Did the presence of nuclear weapons prevent a crisis from exploding into a thermonuclear war? In other words, did deterrence work? Or were the Soviets and Americans simply lucky to avoid a catastrophe? And would such a crisis ever have occurred in a world that had no nuclear weapons?

The final historical lesson may be about the validity of historical lessons themselves. How much of what happened fifty years ago was unique to its time and place, and how much is generalizable to the world we live in today? For decades, policy makers and international-relations experts have crafted theories, morals and rules from this brush with Armageddon and applied them to contemporary foreign-policy dilemmas.

But for the average college student born after the end of the Cold War, the bigger question may be why the Soviet Union and the United States were willing to rest the fate of the world on the placement of missiles that would soon be irrelevant, particularly once the Soviets achieved a secure second-strike force by the mid- to late-1960s (a fact both sides knew). The crisis, like much of the Cold War, seems bizarre. It is still hard to place and make sense of it.