Give the US Army some credit: their solution to the fact that they were ill-trained for fighting in jungles was a simple one. They’d simply get rid of the jungle. While there was some earlier testing of herbicides in 1961, it wasn’t until 1962 that large scale deployment of the Rainbow Herbicides – Agents Pink, White, Purple, Green, Blue and (most infamously) Orange – began. Over the course of ten years, until 1971, nearly 20 million gallons of assorted herbicides would be used.
The policy was largely a failure at its stated goal, but it did do wonders for the bottom lines of various military contractors and led to a boom in birth defects among the children of soldiers and civilians exposed to it on both sides in the years to follow the war.