By 1970, U.S. troops in Vietnam complained of illnesses they blamed on Agent Orange sprayed to defoliate the Ho Chi Minh ​​​​​​​trail and interrupt the food supply of North Vietnam. Troops hit barriers of secrecy and lies, and​​​​​​​ denial. Breaking those barriers took decades and left a legacy of frustration, genetic deformities, death, and the ruined credibility of the U.S. government.​​​​​​​