[1] The widespread use of herbicides in Southeast Asia during the Vietnam War was a unique military operation in that it was meant to kill the plants that provided cover.
The continued use of Agent Blue and the other "Rainbow Herbicides" by the United States was primarily meant as an operation to take away the enemy's advantage on the terrain as well as deprive them of food.
The US found themselves at a disadvantage and based on the precedent set by the British in Malaya, decided that the most vicious (best) retaliation would be to take the Vietcong's advantage away from them by removing their cover.
Along roads, canals, railroads, and other transportation networks, Ranch Hand cleared several hundred yards using the herbicides to make ambushes more difficult for their enemies.
In Laos, the herbicide removed the jungle canopy from the roads and trails used for infiltrating men and supplies, making them more vulnerable to attack from the air.
[6] In 2009, the MSMA uses on athletic fields, parks, residential lawns, forestry, non-bearing fruit and nut trees, and citrus orchards were also canceled.