As the map shows Agent Orange was sprayed over a good part of Vietnam to defoliate the jungle and brush to expose the enemy. By 1971 about 12% of the total area of South Vietnam had been sprayed with defoliating chemicals. Not only did we spoil the Vietnam country side, cause hundreds of thousands of deaths and birth defects; we damaged Vietnam Veterans who had crawled through it and dug fox holes in it.
On the plus side the US has started a multimillion dollar initiative in 2012 to begin to decontaminate the Dioxin hot spots in Vietnam. It is a beginnig.