“In Iraq, they’d hit you and run,” he said. “But these guys stick around and maneuver on you.”

They also have a keen sense of when to fight and when the odds against them are too great. Three weeks ago, the American military mounted a 4,000-man Marine offensive in Helmand  the largest since President Obama’s troop increase  and so far in many places, American commanders say, they have encountered less resistance than expected.

Yet it is also clear to many Marines and villagers here that Taliban fighters made a calculated decision: to retreat and regroup to fight where and when they choose. And in the view of troops here who fought intensely in the weeks before the offensive began, fierce battles probably lie ahead if they are to clear the Taliban from sanctuaries so far untouched.

“It was straight luck that we didn’t have a lot more guys hit,” said Sgt. Brandon Tritle, another squad leader in Company C, who cited the Taliban’s skill at laying down a base of fire to mount an attack.

“One force will put enough fire down so you have to keep your heads down, then another force will maneuver around to your side to try to kill you,” he said. “That’s the same thing we do.”