The two most noxious myths these days about the presidency of John Fitzgerald Kennedy are: 1) JFK was a distracted playboy who accomplished nothing significant in his brief 1,000 days in office, and 2) He was a militant Cold Warrior who was willing to risk nuclear war to keep our Communist foes in their place. Saber-rattling neocons and chest-thumping Democrats are particularly fond of this bellicose image of Kennedy. But my new book, "Brothers" -- which I call a "hidden history of the Kennedy years" -- proposes a very different version of JFK's brief reign.

I portray a president who heroically kept the country out of war -- against relentless pressure from hard-liners in the Pentagon, CIA and his own White House, who were determined to militarily engage the enemy in Berlin, Laos, Vietnam and especially Cuba. Kennedy knew that any such military confrontation could quickly escalate into a nuclear war with the Soviet Union. And he realized that a full-scale invasion of Cuba or Vietnam could become hopelessly bogged down, turning into a bloody and endless occupation.

In fact, even the CIA's own analysts predicted such a nightmarish scenario if Kennedy listened to his intelligence officials and military commanders and invaded Cuba. A National Intelligence Estimate produced in April 1962 predicted that while U.S. military forces would quickly sweep aside Castro's army and take Havana, American soldiers would soon come under fire from the remnants of Fidel's military, as they melted into the countryside and became nettlesome insurgents. U.S. forces would respond to the inevitable terrorist attacks with their own excessive violence, turning the Cuban people increasingly against the U.S. occupation. Meanwhile, America's image would suffer badly around the world as a result of our blundering, unilateral military action. Sound familiar?

The only reason Cuba didn't become the Iraq of its day was that Kennedy was too wise to be snookered by hard-liners into this trap. He had already been misled early in his administration by the CIA, which convinced him that its ragtag army of Cuban exiles could defeat Castro at the Bay of Pigs. JFK vowed that he would never again listen to these so-called national security experts, and following the fiasco, he even threatened to "shatter the CIA into a thousand pieces and scatter it to the winds." The president didn't go that far, but he did fire the CIA's top two officials -- including legendary spymaster Allen Dulles, who was stunned by Kennedy's presumption that the democratically elected president of the United States should run the country's foreign policy, instead of Washington's shadowy national security elite.

Imagine having a president who was not only farsighted enough to recognize the dangers of imperial folly, but who had the fortitude to stand up to the frothing war lobby that seems to call for blood -- others' blood, never their own -- in every administration. "He kept the peace." That's what John F. Kennedy often said he wanted as his epitaph. And it should be. "I think [Kennedy's] view was that the primary responsibility of the president is to keep the nation out of war if at all possible," Robert McNamara, JFK's defense secretary, has commented. McNamara himself would go down in history with a very different legacy. But Kennedy kept true to his peaceful vision until his own violent death.