American officials inspect a field in Helmand, 1960s

Eight years ago, a 72-year-old American aid worker named Charles Grader told me a seemingly fantastical story. In a bleak stretch of Afghan desert that resembled the surface of Mars, several dozen families from states like Montana, Wisconsin and California had lived in suburban tract homes with backyard barbecues. For 30 years during the Cold War, the settlement served as the headquarters of a massive American project designed to wean Afghans from Soviet influence.