Once you're in a war, how do you get out?

• Author: Erwin, Sandra I.
• Position: DEFENSEINSIDER - Between War and Peace: How America Ends Its Wars

* The United States passed a bleak milestone last year: The war in Afghanistan became the longest conflict in the nation's history. Many Americans want to know when and how the war might end. The soldiers who are fighting there may want some answers, too.

In the absence of a crystal ball, the U.S. Army in 2009 asked a number of renowned historians to dig into their archives and elucidate the public on how the nation managed to bring previous major conflicts to a close. The product is a book of essays, titled "Between War and Peace: How America Ends Its Wars." It contains 15 essays penned by leading American historians and edited by Army Col. Matthew Moten, who is deputy chairman of the history department at the U.S. Military Academy at West Point.

"It is curious that in all the hundreds of thousands of books on war and military history, the manner and results of war's end have seldom been addressed in a rigorous and systematic fashion," Moten writes in the book's introduction.

Not surprisingly, one of history's painful lessons is that wars don't achieve what leaders originally intended. For most of its history, the United States has been successful in wars, says Moten. "But the endings of those conflicts have brought about unforeseen and unwanted consequences; the aftermath has seldom resembled the peaceful future the nation's leaders had imagined and hoped for when they first decided for war."

These historians' accounts also are reminders that it is often difficult to pinpoint exactly when a...