Anthony Shadid writes:

Iraq today is replete with American-ordered deadlines, timetables and benchmarks that sought to create realities where realities never existed. The administration is leaving now on its own terms. Perhaps staying would make an already traumatized Iraq worse; much of its dysfunction dates to the American occupation and its earliest days. But the very nature of America’s departure — with no government formed, an unpredictable Iraqi military, and deep popular disenchantment with a hapless political elite — underscores one of the most enduring traits of American strategy in the Middle East.

Powerful but fickle, the United States has never seemed to understand time, at least not in the way it is acknowledged by Islamic activists willing to serve decades in jail, Syrian presidents assured that American policies will eventually change, and Iraq’s neighbors, who bide their turn to fill the vacuum left by an American departure.

Its policies — support for Israel and authoritarian Arab governments, the invasion of Iraq and war in Afghanistan — may shape sentiments toward it. But time, an American measure of it, often shapes the way it acts.

“It certainly is American politics and it is American culture, the sense that we are an impatient people,” said Ryan C. Crocker, a former ambassador to Iraq and veteran diplomat in the Arab world. “ ‘Tomorrow or the day after tomorrow, at the latest, and if that’s not going to happen, we’re going to move on.’ ”

The Middle East has long suffered under a peculiarly American notion that if the world’s greatest power wants something, it will somehow come to pass, on its schedule. In Lebanon, the Palestinian territories and Syria, the messy realities never quite fit. Since 2003, they rarely have in Iraq, either.