sixty one were manufactured and sold by american chemical companies including dow monsanto and diamond shamrock. at that time vietnam was divided into north and south the us supported the government of south vietnam and military intervention intensified after nine hundred sixty five. but the us made strong resistance from guerrilla forces who used dense jungle as their base of operations. defoliants brain was begun in an effort to deny cover to the guerrillas by eliminating the jungle folly which. as the war escalated the spring of deval eons increased dramatically and much of the land in south vietnam was contaminated and left barren. the defoliant known as agent orange was made from the same chemical substances as herbicides used in the us but it was twenty five times more potent. agent orange also contained dioxin the most toxic chemical ever produced. dioxin remains in the environment for many decades and causes a variety of health problems. several million vietnamese and american soldiers who fought in vietnam were affected by agent orange. their children and grandchildren continue to suff