Which best describes the main goal of those who opposed the Vietnam War in 1969? Immediate withdrawal of US troops from South Vietnam. The opponents of the Vietnam War believed that US involvement was unjustified. Antiwar protests increase after they saw, as an escalation of the war, the attacks that US forces made in Viet Cong bases. The later years of the war saw increased physical/psychological deterioration among American soldiers, including drug use and post-traumatic stress disorder. A strong anti-war movement among American forces spawned violent protests. Opponents of the war argued that civilians were the primary victims. All US troops had left South Vietnam by the end of March 1973.