Robert H. Scales, a retired U.S. Army major general and former commandant of the Army War College, is president of the consulting firm Colgen.

I guess I knew it would eventually come down to this: Blame the Army’s institutions in some way for the horrific and senseless slaughter of 16 innocent Afghan civilians in Kandahar, allegedly by a U.S. infantry non-commissioned officer (NCO). In their search for a villain, the media seems to be focusing now on Joint Base Lewis-McChord in Washington state, where the accused soldier was stationed before his fourth deployment to a combat zone.

Before we get too involved in attacking institutions, perhaps it might be right and proper to suggest that the underlying issue here is not about failure of our Army. Perhaps the issue might be that no institutional effort can make up for trying over the past 10 years to fight too many wars with too few soldiers?

The accused NCO is an infantryman. Two weeks ago I talked with infantry soldiers at Fort Benning, Ga., and I couldn’t help contrasting them with those of my generation of Vietnam veterans. What caught my attention were the soldiers’ amazing stories of patient, selfless, introversive commitment. First I took to heart the enormous disparity in stressful, extreme experiences between the infantry and other branches and services that have come back from Iraq and Afghanistan. The senior NCOs I spoke to all had at least three, and in some cases five, tours, virtually all in close combat units. Contrast this with returning Vietnam NCOs and junior officers, most of whom in that era had only one tour in Vietnam.

Of course infantry combat in Vietnam was perhaps more intense, but close fighting in Iraq and Afghanistan was more pervasive and lasting, thus more likely to cause personal trauma in my mind. The infantrymen I spoke to at Fort Benning were different from those in my generation. They were more emotionally exhausted and drained, less spontaneous and humorless. My generation of professionals spent a great deal of time on Friday nights at the officer’s club, talking over a beer about the Catch-22 nature of Vietnam and many of the stupid and hilarious experiences we endured. None of this at Benning today. No clubs, no public displays of hilarity and certainly no beer. These guys seemed to view their time in combat as endless and repetitive. My sense is that their collective, intimate exposure to the horrors of close combat was far more debilitating than what we experienced.

This of course in no way justifies what happened in Kandahar. But I think if someone wants to place blame, it should be on a succession of national leaders who fail to recognize that combat units, particularly infantry, just wear out. Lord Moran concluded in his classic about combat stress in World War I, “Anatomy of Courage,” that the reservoir of courage begins to empty after the first shot is fired. The horrors of intimate killing, along with other factors such as fatigue, thirst, hunger, isolation, fear of the unknown and the sight of dead and maimed comrades, all start a process of moral atrophy that cannot be reversed. Lord Moran rightfully concludes that nothing short of permanent withdrawal from the line will bring soldiers back to normalcy.

The media is trying to make some association between the terrible crime of this sergeant and the Army’s inability to treat post-traumatic stress disorder and traumatic brain injury. Perhaps the Army could have done more. But I think Lord Moran had it more right; the real institutional culprit is the decade-long exploitation and cynical overuse of one of our most precious and irreplaceable national assets: our close combat soldiers and Marines.

If someone just after 9/11 would have told me that a very small Army and Marine Corps would fight a 10-year-long set of close combat engagements in two wars and still remain intact, I would have called them crazy. Well, we’ve done just that, haven’t we? But at what cost to the few who have borne an enormously disproportionate share of emotional stress?