All of Washington is reading an inch-thick tome by a West Point graduate with a Ph.D. from Johns Hopkins and a 300-page meditation on the life of McGeorge Bundy by a young man who manages a Brookings Institution project on sovereign wealth funds.

Does anybody talk about McGeorge Bundy — the youngest dean of the faculty in Harvard history, then one of the architects of John F. Kennedy’s Vietnam policy — anymore?

Apparently people do. You can’t find a copy of Gordon M. Goldstein’s “Lessons in Disaster” anywhere in Washington (and every copy in every library in my home county is checked out). It’s the story of the early 1960s American rendezvous with disaster in Vietnam, a volume that veteran diplomat Richard C. Holbrooke described in a New York Times review in these glowing terms: “On the long shelf of Vietnam books, I know of nothing quite like it.”

The other book in the Obama reading circle this autumn is Lewis Sorley’s “A Better War: The Unexamined Victories and Final Tragedy of America’s Last Years in Vietnam,” and it concludes that the Americans, contrary to accepted wisdom, “came very close to achieving the elusive goal of a viable nation and a lasting peace.”

These two volumes are being devoured as the Obama administration conducts a prolonged and agonizingly public debate over which way America should go in Afghanistan. Obama himself was born only six months into the Kennedy administration and as one of the youngest baby boomers — that demographic category would close out when he was 3 years old — does not possess the Vietnam obsession and preoccupation of his elders.

Nonetheless the surface parallels between Vietnam and Afghanistan (both Asian nations, both heirs to failed colonial rule, both torn apart by post-colonial strife, both infected by irredentism and irreconcilable warlords) are alluring, just as the parallels between Vietnam and Iraq were alluring in the Bush years, and just as the parallels between Vietnam and Lebanon were alluring in the Reagan years. Vietnam sure is a malleable metaphor.

Not since the days when John F. Kennedy told his advisers to read Barbara Tuchman’s “The Guns of August,” on the beginning of World War I, has Washington been on such a reading binge. The value of the Tuchman volume wasn’t the lessons it taught about how corrupt empires presided over by czars, kings and kaisers could bring a continent to disaster, but how seemingly separate events could conspire to force rational decision-makers to make irrational choices.

It is chilling to realize that the distance between the early days of the Kennedy years and the beginning of World War I is exactly the same as the distance between the current reassessment of Afghanistan policy and the infancy of the American Vietnam policy.

Ordinarily the notion of Washington on a reading binge is a comforting rather than a troubling thing. May I suggest that the entire Congress be required to read “The Great Triumvirate,” the greatest account of the lives and careers of Webster, Calhoun and Clay, written by Merrill D. Peterson, the University of Virginia historian who died this autumn?

But the questions before us now are whether history really can be allegory — and whether Vietnam poses the right questions or provides the right lessons for Afghanistan.

Goldstein says there are lessons from Vietnam, and indeed one of his chapter titles comes from a lesson Bundy learned too late: “Never Deploy Military Means in Pursuit of Indeterminate Ends.” But he also knows the dangers of too literal a learning of lessons from history. “The danger,” he said in a telephone conversation the other morning, “is that Vietnam can be a prism through which we distort and simplify complex military challenges.”

He’s right about that. We’ve made the mistake of learning a lesson not wisely but too well before. We almost always forget that Vietnam in fact represented a tragic mixing of metaphors.

The misapplication of the lessons of Munich, the 1938 debacle that made any hint of appeasement seem like a moral and geopolitical sin, has been a stigmata on the American body politic for two generations. It was almost certainly (here comes another mixed metaphor, an Old Testament image to accompany one from the New Testament) the original sin of the Vietnam strategists.

The differences between Afghanistan and Vietnam are subtle but important. “South Vietnam for a long time was part of a French-administered system,” says Thomas J. Vallely, who directs the Vietnam Program at the Kennedy School’s Center for Business and Government at Harvard. “There was some state effectiveness in Vietnam. There were universities and hospitals. It was a 20th-century country. It may not have had all the bells and whistles, but it had a lot more than Afghanistan.”

So it is wise to recognize that all Asian nations are not the same, a basic distinction that we can assume will not be lost on a president reared as a young boy in Indonesia. That is not the issue. It’s the process of presidential decision-making that is the question today. It is also the threat.

Presidents should study history, be guided by it, apply its analyses widely — but carefully. Because one of the lessons of history is that, in the end, there are no real lessons from history for a president who is looking at a crisis that, like most of them, is created by history.