It was 3rd Platoon’s first gunfight in Zari and, for many of the roughly 20 young soldiers, their very first time under fire. “We were like, what’s this?” recalls Spec. Joshua Cripps, a mouthy young marksman. The Americans reacted instinctively, diving for cover between the 8-foot-tall earthen berms that double as vine trestles. Afghan army troops returned fire, giving the Americans time to organize a direct assault on the attackers’ positions.

One Taliban fighter was wounded and the others fled. No one on the U.S. side got hurt.

Gunsmoke cleared, pulses slowed and the patrol continued. And that’s when Toorjan announced that, in fact, there was no informant — he’d been mistaken all along. Only later, after much more exposure to unusual police behavior, would the 3rd Platoon troopers reflect … and suspect that maybe Toorjan had set them up that day in Hadji Musa.

Over the course of a tense six months in Zari, 3rd Platoon and the rest of Bravo Company would encounter case after case of sketchy behavior by the ALP, possibly indicating that the local police — either willingly or through coercion — had switched sides and were now actively aiding the Taliban.

It’s a disturbing possibility with huge implications for the coalition. U.S. officers in Zari say tips from the local cops are supposed to be their main source of battlefield information. If the American-led NATO coalition can’t trust the local police, it can’t trust much of what it thinks it knows about Afghanistan — and its plans for the war-ravaged country’s future could be in big trouble.