In the 1960s, the United States blanketed the Mekong River delta with Agent Orange, a chemical defoliant more devastating than napalm. Thirty years after the end of the Vietnam War, the chemical is still poisoning the water and coursing through the blood of a third generation. From Ho Chi Minh City to the town of Ben Tre—and from Greensboro, North Carolina, to Hackettstown, New Jersey—the photographer James Nachtwey went in search of the ecocide’s cruelest legacy, horribly deformed children in both Vietnam and America. Nachtwey, arguably the most celebrated war photographer of his generation, sees the former conflict in Southeast Asia as a touchstone for his work. “My decision to become a photographer,” he says, “was inspired by photographs from the Vietnam War.” This expanded photo essay from the land of Agent Orange—part of which appears in the August V.F.—makes clear, according to Nachtwey, that “the effects of war no longer end when the shooting stops.”