MacDILL AIR FORCE BASE, Fla. – The ticking clock does not disturb the preternatural serenity that Gen. David Petraeus maintains regarding Afghanistan. Officially, the U.S. Central Command is located here; actually, it is wherever he is, which is never in one place for very long. He is away about 300 days a year, flying to and around his vast area of responsibility, which extends from Egypt to where his towering reputation is hostage to a timetable – Afghanistan.

He earned his own chapter in American military history by advocating and presiding over the surge that broke the back of the Iraq insurgency. This was an instance of a military intellectual given full opportunity for the unity of theory and practice.

Today, however, only about half of the surge of 30,000 troops for Afghanistan, announced by the president in his speech at West Point five months ago, have arrived. The rest will be there by the end of August. Eleven months after that, the withdrawal the president promised – in the sentence following the one that announced the increase – is supposed to begin.

But Petraeus cautions that the president’s words, properly parsed, allow ample time to achieve U.S. objectives. The president said on Dec. 1 that the “transition of our forces out of Afghanistan” must be “responsible,” which means “taking into account conditions on the ground” and allowing for improved “Afghan capacity.”

Petraeus, who likes fine distinctions, speaks of “thinning out” rather than “handing off” U.S. involvement, which is “what we’re still doing in Iraq.” This will take time because counterinsurgency in an underdeveloped society is, inescapably, nation-building. Which brings us back to the ticktock of the clock.

Petraeus believes that, “valley by valley and village by village,” skillful policy “can break up the Taliban,” much as Sunnis were peeled off the Iraq insurgency. But the recent withdrawal of U.S. forces from the Korengal Valley was evidence of a changing mission: Rather than contest every valley and village, Petraeus wants to concentrate on protecting population centers where more than 70 percent of Afghans live.

That, however, might mean ceding to the Taliban control of as much territory as it held when Osama bin Laden arrived in 1996 to begin plotting the operation that came to fruition five years later. Furthermore, because the Taliban is not a transnational terrorist organization, the reason America has identified defeating or taming the Taliban as a “vital national interest” pertains to territory: Otherwise al-Qaeda could again have space to train and plot under Taliban protection, or indifference.

Petraeus speaks less about decisively defeating the Taliban militarily than of the “reintegration” of lower-level Taliban into society and “reconciliation” of the higher level. This might seem like a piece of cake if you were, as he was, involved in the darkest days in Iraq. In December 2006, at the height of Iraq’s sectarian violence, an average of 53 bodies – often decapitated and lacerated by torture – were found on Baghdad streets every 24 hours. Afghanistan’s capital, Kabul, is, he says, tranquil, other than the occasional car bombs, which are not strategically significant.

Petraeus, who has a flair for understatement, says Afghanistan “is a bit of a kaleidoscope of different groups.” That complicates counterinsurgency, concerning which he wrote the book – the 472-page U.S. Army/Marine Corps Counterinsurgency Field Manual. The three prongs of counterinsurgency – “clear, hold and build” – involve three entangled problems.

First, is an area “cleared” only because the Taliban have cleared out, knowing they can wait out the enemy and then return? The Americans are going home; the Taliban are home. Second, what can be held by a counterinsurgency force focused on an exit strategy? Third, can anything lasting be built when what has been only tenuously cleared is only conditionally held?

The answer to those questions must involve defusing an insurgency by means of a political settlement, after the insurgency has been weakened by the application of violence, and sapping its ardor with new institutions and economic infrastructure. Again, nation-building.

What Petraeus calls “a whole of government approach” does not promise a tidy ending of “take the hill, plant the flag, go home for a victory parade.” Turning off an insurgency is “never a light switch, it’s more of a rheostat.” He recounts a story: An Afghan waits 99 years for vengeance, then regrets his impatience. This parable gives a serrated edge to a familiar Afghan aphorism regarding outsiders – “You have the watches, we have the time.” Tick, tick, tick.

© 2010, Washington Post Writers Group