I met Luong Hoai Thuong in 2007 when I was photographing in Vietnam. I was particularly interested in landmine survivors, and after a couple of days of capturing images of amazing adults who had lost their arms but could still manipulate a hoe in their fields or had lost legs but could still fish for shrimp in ponds formed from bomb craters, I met this little girl, who is here doing her homework. She was born without her left hand, a birth defect caused by Agent Orange. During the Vietnam War (what's known as "the American War" to the Vietnamese), the U.S. military sprayed Agent Orange over forests and farmland in an attempt to deprive the Viet Cong of cover and food. The dioxin compound used in the defoliant is a long-acting toxin that can be passed down genetically, so it's still having an impact more than four decades later. The Vietnam Red Cross estimates that some 150,000 Vietnamese children are disabled owing to their parents' exposure to the chemical. Symptoms range from diabetes and heart disease to physical and learning disabilities. This girl's sister, who I also photographed, has some serious learning disability. But Hoai Thuong is a sharp kid, and besides whipping quickly through her homework, she handily beat me and her sister at a game of jacks. I often photograph children who are victims and survivors of all sorts of violence, and it's never easy, but there's something particularly insidious about how Agent Orange lingers in mutated DNA, whether in the children of Vietnamese farmers or the children of U.S. military veterans. The true cost of war, in any land, is always exponentially more than its apologists claim. It's time we stop believing them.