The Department of Defense is concerned about the 30 percent higher suicide rate among troops stationed in Iraq. The normal rate is 13 per 100,000 troops per year, but it is 17 in Iraq (11 soldiers and three marines so far). Another dozen or so accidental deaths are being investigated as possible suicides. About one in three hundred soldiers have been sent home for "mental health" reasons. The army has had similar problem in the past. Vietnam, Korea and World War II produced higher than usual rates of suicide and mental problems in combat zones. Vietnam and World War II demonstrated that the problems were most severe during "irregular warfare" (ambushes, snipers, lots of patrols.) In the decade after the Korean war ended, there was a much higher suicide rate among troops stationed on the DMZ. The landscape was grim and depressing and the duty monotonous. The army's concern is probably mostly a result of no one remembering the statistics on these problems from past wars. In addition, the army has been trying to screen it's recruit to keep out those who could not handle the mental stress of combat. But you don't get to test how well your screening is until you actually have a war.