During the Vietnam War, the United States used chemical weapons such as the defoliant Agent Orange. The US wanted to defoliate the jungle in order to make North Vietnamese troops and camps more visible from the air, so they destroyed the canopy of leaves. In this photo, palm trees in a South Vietnamese village show the effects of Agent Orange.
These are the short-term effects of the chemical defoliant. Long-term effects include a number of different cancers and severe birth defects among the children both of local villagers and fighters, and of American Vietnam veterans.