In the United States since the conclusion of the Vietnam War, the Vietnam veteran has become known as a neglected, troubled, and even scorned individual. According to this view, the Vietnam veteran's problems began in Vietnam where he was forced to participate in a brutal and disturbing war in which he was under fire twenty-four hours a day. The enemy, the wily and tenacious Vietcong and North Vietnamese regulars, were not always clearly defined nor were they above hiding behind or using civilians, leading to the unintentional – and sometimes intentional – killing by American forces of noncombatants, including women and children. Due to the military's policy of limiting the tour of duty in the war zone to one year, combat groups lacked cohesion and suffered from low morale, resulting in the excessive use of marijuana and heroin and an eventual breakdown of discipline, leading to the “fragging” of officers who attempted to reimpose order.
