As the American involvement in Vietnam escalated so did the use of herbicides, Operation Ranch Hand was expanded to include parts of southern and eastern Laos in December 1965. The herbicide program reached its peak in 1967 when over a million and a half acres were sprayed.

While much of the earlier hesitancy to conduct the herbicide program revolved around concerns of its efficacy, there were also concerns in Washington about how the use of chemical herbicides would be perceived in the world community and how the North Vietnamese government would use the herbicide program as a propaganda tool. None the less, Secretary of State Dean Rusk assured President Kennedy that the use of herbicides was an acceptable war tactic and did not violate