May 31, 2009: U.S. military deaths in Iraq have spiked in May, reaching 22. This is the highest number of deaths there since last September, when there were 25. But five of those May deaths were the result of an American soldier going berserk in a medical clinic, and killing five other U.S. troops. Such incidents are rare, but not unknown, even in peacetime. Most of the May deaths were not combat related.

So far this year, there have been 83 deaths in Iraq, compared to 314 in 2008 and 904 in 2007 (the peak year for these deaths). In the last eight months, U.S. troops in Iraq have had more to fear from accidents, disease and stress, than enemy action. In those eight months, 130 troops died, but less than half as a result of combat. This is a trend that has been growing for over a year.

Through the end of last year, 4,300 U.S. troops have died in Iraq, and 19 percent of those fatalities were from non-combat causes. Most of the non-combat deaths were from accidents and disease. One of the major categories of non-combat death is vehicle accidents. In 2007, 20 percent of the non-combat deaths were from vehicle accidents. But in 2008, overall deaths declined by two thirds (from 904 in 2007, to 312 in 2008), but vehicle accident deaths went from 37 to 19.

The U.S. Army expected vehicle accidents to decline even more in 2008, because the number of terrorist incidents went down by 80 percent. Many vehicle accidents were the result of the fast driving tactics troops were encouraged to use to get away from roadside bombs and ambushes. Ask the NCOs, and they will often complain that the sharp reduction in combat has removed the incentive to stay sharp and pay attention. Not a unique situation in a combat zone, and despite the energetic exhortations of the NCOs, too many troops do not stay alert enough to avoid accidents. Ask the troops, and they complain about the heavier traffic. With peace breaking out all over central Iraq, and the economy continuing to boom, more Iraqis have cars. Iraqis drive like they're from Boston, with abandon and indifference.

Meanwhile, military experts around the world are still trying to make sense of how the United States has kept its casualties so low in Iraq and Afghanistan. To put it in simple terms, you were three times more likely to be killed or wounded in Vietnam (or World War II), compared to Iraq. And then there is the mystery of higher non-combat deaths in Afghanistan. In Vietnam, and Iraq, 19 percent of the deaths were from non-combat causes (accidents, disease, for the most part.) During World War II, 25 percent of the dead were non-combat. In Afghanistan, 29 percent of the deaths were non-combat, and that is rapidly increasing as combat deaths plummet. But even before the current decline in combat casualties, Iraq had a greater variety of diseases, and nasty terrain (including the atrocious roads).

What the U.S. did was put in well trained, led, armed and motivated troops and then supported them lavishly. Civilians were hired to do a lot of the menial jobs. Much effort was put into getting to know the local culture, and avoiding civilian casualties. That eventually won over enough Iraqis to undercut support for Islamic radicals (mostly Sunni Arabs angry at no longer being in charge, and minority Shia groups keen on setting up a Shia religious dictatorship).

But while the diseases and safety situation in Iraq is improving, there's still a way to go in Afghanistan. The many diseases, bad roads, hills and mountains will remain for some time to come. Afghanistan will remain a dangerous place, even if no one is shooting at you.