The U.S. Army is suffering its fourth straight year of increasing suicides among active duty troops (140 for the first ten months of this year, 140 last year, 115 in 2007 and 102 in 2006.) Things like suicide rates are measured in how many people per 100,000 population are affected. The active duty strength of the army is over half a million troops (including a fluctuating number of activated reservists). Thus the suicide rate in 2008 was 20 per 100,000 troops . In 2007 it was 19. The rate in 2006 was 12.8, and for the last decade, had fluctuated between 10-13 per 100,000. The suicide rate for troops in Iraq has been about 40-50 percent higher than for soldiers stationed elsewhere. The suicide rate for the entire U.S. population is about 11 per 100,000.
The U.S. Marine Corps suicide rate has gone from 16 per 100,000 in 2001 to 22 per 100,000 last year. That was the first year of a spike, as the rate was 13 per 100,000 in 2006. This year, the rate is expected to be 23 per 100,000 troops.
Both the army and marines have introduced several programs to identify and treat those at risk for suicide. This effort is linked with the overall program of dealing with combat stress. Because of much reduced casualty rates (a third of those in Vietnam and World War II), far more troops are spending more time in combat. During World War II it was noted that troops could only take so much combat stress before they developed debilitating mental problems. The military has developed many programs to counteract the stress, but nothing that can eliminate it.
It's well known that the suicide rate in the military is linked to stress. For example, back in 2005-6, the U.S. Navy was concerned when the suicide rate among submarine crewmen went to 35 per 100,000. At the time, the rest of the U.S. military Army had a rate about a third of that (about ten per 100,000 uniformed personnel). The suicide rate for submariners was eventually brought down to 20 per 100,000, mainly because the navy identified the causes of the stress and did something about it. But it's always understood that the suicide rate among the 20,000 submarine sailors will be higher, simply because it's more stressful work.
Non-combat stress can create an even higher suicide rate. The Russian military has a rate of 33 suicides per 100,000 troops (that's over 300 suicides). This is declining, but not fast enough. Russia is not at war, except for a small force in Chechnya, where they face remnants of separatist and Islamic terrorist groups. The Russian problem is institutionalized brutality of senior troops towards junior troops. This has been a problem since the end of World War II, and the government has been trying to fix it for over a decade now.
The U.S. Army notes that the suicide rate has been declining since early in the year, indicating that all the treatment efforts are paying off.