"[T]hey are not going to permit nuclear weapons to be used against the United States from Cuba unless they're going to be used from every place."

It was what they all had been thinking. If the Soviets were serious about using the atomic arms they had smuggled into Cuba, we were only one step away from a worldwide nuclear war.

It was Oct. 18, 1962, when President Kennedy voiced his concerns to the ExComm -- the Executive Committee of the National Security Council. The group consisted entirely of members of the president's inner circle, each specially chosen to help manage the Cuban Missile Crisis.

Organizing the ExComm was an unprecedented initiative for an unprecedented crisis. When summing up the latest Cold War revelations, John Lewis Gaddis concluded, "With all their new evidence, historians have yet to alter their view that this was the point at which the world came closest" to nuclear combat.

What has altered, though, is our understanding of how JFK managed the crisis. For decades, the ExComm was viewed as crucial, the brain trust that the young, inexperienced president relied on to guide him through the difficult days. But Gaddis describes a different picture: "Far from relying on the ExComm, [Kennedy] bypassed it at the most critical moments."

Over the years, historians have drawn from the Cuban Missile Crisis all kinds of "lessons" -- from how to manage a crisis to how to prevent nuclear war. In practice, none may be particularly useful for presidents in managing future predicaments. Every confrontation has a character all its own, making each crisis unique. What Iran's Mahmoud Ahmadinejad might do with his nuclear weapons (if and when he gets them) could well be different from how the Soviets' Nikita Khrushchev managed his atomic arsenal.

Still, as we approach the 50th anniversary of this "Day that Shook the World," there is one vital and unimpeachable lesson from the showdown that we should remember: that in the American system, when it comes to national security and foreign policy, the president is the chief decider. A commander in chief may convene a committee for its members' advice and council, but in the last full measure, these decisions are the president's and the president's alone.

What better time to reflect on that truism than during the prelude to a presidential election? All Americans -- right, left and center -- expect their president to "provide for the common defense," as the Constitution requires. Most of us pretty much assume that any occupant of the Oval Office will do that, so we tend to select our candidates based more how we think their policies will affect our pocketbooks. But whether the presidential politics succeeds in making us richer or poorer, one thing is certain: The president is the one who picks up the 3 a.m. phone call.

This year, voters will have a very clear choice when deciding who they want as the chief decision-maker for the next four years. At the presidential debate focused on foreign policy, we can expect the two candidates to agree on only one point: that they have very different visions of how to provide for the common defense.

Sometime over the next four years, the occupant of the White House can expect to face a "missiles of October" moment, albeit one with its own, unique characteristics and complications. How well the nation weathers that crisis will be determined largely by the decider the American people choose to put in command next month.

Examiner Columnist James Jay Carafano is a senior research fellow for national security at the Heritage Foundation.