August 10, 1961. On this day the first American aircraft sprayed chemical herbicide over the Vietnamese countryside, opening a program whose damage is still killing people more than sixty years later. It is why August 10 is now marked as Agent Orange Awareness Day. The idea sounded almost bloodless on paper. It was called Operation Ranch Hand, and the plan was to spray defoliants from low flying planes to strip the jungle bare so the enemy could not hide under the canopy, and to destroy crops so the enemy could not eat. Between 1962 and 1971 the United States poured an estimated 20 million gallons of these chemicals over Vietnam, Laos, and Cambodia, turning green forest into gray skeleton and killing farmland across huge stretches of the country. The most infamous of the mixtures was Agent Orange, named for nothing more sinister than the orange stripe painted around its 55 gallon drums. Inside was a chemical contaminated with dioxin, one of the most toxic substances known, poisonous in amounts almost too small to measure. Nobody spraying it in 1961 was told what it would do to human beings. What it did was monstrous, and it did not stop when the war did. Vietnamese by the hundreds of thousands, and American veterans who walked and slept and bathed in that sprayed ground, came down with cancers, nerve damage, and a long list of diseases. Worst of all, the dioxin reached into the next generation, and children were born, on both sides, with terrible birth defects, in Vietnam and in the homes of American veterans alike. For years the US government insisted there was no connection, and men had to fight for decades to get their own country to admit that the chemical it ordered them to handle was the thing that was killing them. August 10 is not the anniversary of a battle. It is the anniversary of a decision, and a reminder that some of this war's worst casualties were never shot. They were poisoned, slowly, and some of them had not even been born yet.