“I know that I want it to be an effective traditional or classic counterinsurgency campaign by getting people down in among the population,” the general said. “I know that’s easier said than done with a limited-sized force.”

That last part is a reference to how he doesn’t know, as Spiegel puts it, “whether the planned troop levels for the job he envisions will be adequate.” He’ll find himself first needing to convince Defense Secretary Bob Gates, who earlier this year expressed wariness about increasing troop levels beyond the (mostly-provided) 30,000 requested by McChrystal’s predecessor, Gen. David McKiernan.

But leave that aside for a second. A “classic counterinsurgency campaign” may not be totally possible in Afghanistan. Col. Christopher Cavoli, who later this year will become one of McChrystal’s brigade commanders, observed at yesterday’s Center for a New American Security conference that Afghans aren’t so keen on allowing foreign forces into their villages absent “a pretext” — a discrete event or offer of specific material support — and so “getting down in among the population” can’t work the way it did in Iraq, where U.S. troops in Baghdad literally moved into bases with Iraqi security forces in the middle of various neighborhoods to provide a continuous presence. “You can’t commute to this fight,” Gen. David Petraeus famously wrote in a commanders’ guidance last year. “Living among the people is essential to securing them and defeating the insurgents.” Yesterday at CNAS, Petraeus conceded that wasn’t really applicable in Afghanistan.

So if rule No. 1 of counterinsurgency is to Adapt to Local Circumstance, that has to top all other rules. So the questions confronting McChrystal will have to be what kind of continuous protection can his troops provide for the population if they can’t live with the Afghans; how will local knowledge be employed to gather intelligence against the Taliban-led “extremist syndicate”; and how can U.S. and NATO troops at least shorten their commute to the fight.