MARJA, Afghanistan — Since their offensive here in February, the Marines have flooded Marja with hundreds of thousands of dollars a week. The tactic aims to win over wary residents by paying them compensation for property damage or putting to work men who would otherwise look to the Taliban for support.

The approach helped turn the tide of insurgency in Iraq. But in Marja, where the Taliban seem to know everything — and most of the time it is impossible to even tell who they are — they have already found ways to thwart the strategy in many places, including killing or beating some who take the Marines’ money, or pocketing it themselves.

Just a few weeks since the start of the operation here, the Taliban have “reseized control and the momentum in a lot of ways” in northern Marja, Maj. James Coffman, civil affairs leader for the Third Battalion, Sixth Marines, said in an interview in late March. “We have to change tactics to get the locals back on our side.”

Col. Ghulam Sakhi, an Afghan National Police commander here, says his informants have told him that at least 30 Taliban have come to one Marine outpost here to take money from the Marines as compensation for property damage or family members killed during the operation in February.