Just before dawn on Nov. 18, 1967, the men of the Army’s 266th Chemical Platoon
The men had a typically busy day ahead of them. Their tasks included obtaining 15 drums of Agent Orange to defoliate the base perimeter, firing mortars at an area just outside the base for an evening chemical drop, working at the bomb yard to prepare 24 drums of CS tear gas, making 48 white phosphorus fuses to detonate the drums, loading the drums onto a CH-47 cargo helicopter, and finally, that afternoon, dropping 24 drums of the gas from the helicopter’s rear hatch onto a target site. It was, by 1967, just another day in the life of the 266th Chemical Platoon, and in the American war in Vietnam — a war that was, in many respects, a chemical war.
It didn’t start that way. But as the conflict deepened, it became obvious that chemical weapons could play a critical role. In the case of the First Division, that realization came as the Viet Cong dug in north of Saigon with a network of underground bunkers and tunnels that were forbidding, dangerous spaces where conventional weapons would have limited effect. That fall, the 266th and other chemical platoons began training to use CS and other chemicals to support combat operations.
CS wasn’t the only tool in the platoon’s arsenal, and going after tunnels wasn’t its only mission. It handled anything related to chemicals, from spraying for mosquitoes to burning trash. It sprayed defoliants like Agent Orange and prepared napalm. Chemicals were everywhere, and their proliferation in the American war effort raised concerns that the United States was crossing a line in Vietnam, violating the 1925 Geneva Protocol’s prohibition against the first use of chemical weapons in war.