No matter how hard we look, there may never be an adequate explanation for what Army Staff Sgt. Robert Bales is accused of the massacre of 17 Afghan civilians, nine of them children.
What this atrocity can do what it should do is get us to squarely face some hard truths.
One is that the burden of fighting the war on terror has been unfair. It has fallen on the less than 1 percent of Americans who volunteer for the military. During the past decade, they have been repeatedly sent into combat, serving longer than almost any U.S. troops ever.
Another truth is that as U.S. forces complete their withdrawal from Iraq and pull out from Afghanistan, more than 1 million military personnel will return home over the next five years. What kind of welcome they will receive is very uncertain.
I've been reporting and writing about veterans in recent months for California Forum vets coping with traumatic brain injury, new benefits for wives and other caregivers, new courts to keep veterans out of prison, veterans trying to find jobs or go back to college.
What I've learned is that lots of money is being spent, some innovative programs are being started and that there has been progress.
What I've concluded is that we're not ready for the surge back home, not by a long shot. We're going to be paying for the wars long after we declare victory and leave.
Fred Gusman is executive director of the Pathway Home in the Napa Valley, a nationally known residential center that has treated about 320 combat veterans since opening in 2008.
He says most of the public expects that veterans will quickly and easily return to civilian life. That's unrealistic for many after years in war zones, where they go through physiological and psychological changes, he says.
"We don't have a clue yet that we have a major public health problem on our hands," he told me.
This week, Iraq and Afghanistan Veterans of America will descend on Congress for its "Storm the Hill" lobbying campaign, this year focusing on more aid for unemployed vets.
Among those lobbying will be Jason Hansman, membership director for the 140,000-strong group. He knows Bales will be a topic of conversation when he raises concerns such as brain injuries, post-traumatic stress and financial strains on military families.
While the civilian deaths are obviously tragic, he told me, "It's also tragic that this is how these issues get headlines."
Hansman spent 11 months in Iraq and 81/2 years in the Army Reserves. Like all of us, he was shocked by the horrible news that on March 11, a U.S. soldier allegedly went into two hamlets outside his base, methodically executed 17 villagers, set some bodies on fire and returned to base to surrender.
Ever since the military identified Bales, 38, as the alleged killer, reporters have been rummaging through his life, searching for clues for what may have triggered the carnage.
Bales enlisted shortly after 9/11. He was 27 and a stockbroker who had been fined and had his license suspended after clients accused him of fraud.
He first deployed to Iraq in November 2003, and during his three tours saw some bloody battles. He suffered a traumatic brain injury (the "signature," but poorly understood, wound of the war), lost part of a foot and may have developed post-traumatic stress.
He missed the births of his two children. When he was home, he had some brushes with the law, including a drunken driving arrest and a hit-and-run.
Last year, he failed to get a promotion. He did not want to go to Afghanistan last December, for his fourth tour. Because his family was having financial problems, he was forced to put his home for sale in suburban Tacoma, Wash., three days before the rampage.
The day before the massacre, Bales saw a land mine blow off the leg of a fellow soldier. He reportedly drank afterward. He was nearing 1,200 days in combat.
Some people have suggested that the fact he was repeatedly cleared for duty shows how stretched thin the military is and how poorly it screens soldiers for warning signs. But we may never know what made him "snap."
The intense spotlight on Bales, who was charged Friday with 17 counts of premeditated murder and who is being held at Fort Leavenworth, Kan., shouldn't blind us to the fact that while he may be a symbol, he is the exception.
Hansman served in the same brigade as Bales and overlapped with him for about two months in Iraq, but never met him. He says what happened "puts all vets in a bad light," so the IAVA is trying to present the true face of this "new greatest generation" of veterans.
Thousands upon thousands of Americans have shown discipline and character while serving in Iraq and Afghanistan. They and their families have survived financial and emotional struggles. They have served with honor. They're the ones who deserve our attention, thanks and help.
Gusman of the Pathway Home says he hopes that the Bales case "becomes a catalyst to start asking questions." What kinds of problems are returning vets experiencing? What kinds of services are available? What more can be done to ease their return home?
Those answers will be far more important and productive than what may have made one troubled soldier do the unthinkable.