The raid took place after dark in a remote corner of northwestern Afghani­stan. The target: a drug and weapons bazaar, where the proceeds from selling opium help fund the Taliban insurgency.

Two military helicopters carrying several dozen American soldiers and U.S. Drug Enforcement Administration agents swooped down near the village of Darrey-ye Bum. Among those on board was special agent Michael Weston, a 37-year-old Harvard Law School graduate who’d already been deployed to Iraq as a Marine three times.