What made Dzhokhar Tsarnaev commit terorrism?

In this undated photo provided by Robin Young, Dzhokhar A. Tsarnaev, left, and Here & Now host Robin Youngís nephew, right, pose for a photo after graduating from Cambridge Rindge and Latin High School. Tsarnaev has been identified as the surviving suspect in the marathon bombings. Two suspects in the Boston Marathon bombing killed an MIT police officer, injured a transit officer in a firefight and threw explosive devices at police during a getaway attempt in a long night of violence that left one of them dead and another still at large Friday, April 19, 2013. (AP Photo/Robin Young)

ARLINGTON, Mass. - What made Dzhokhar Tsarnaev do what he did? My memories of Chechnya suggest some possibilities.

His high school history teacher, Larry Aaronson, says the youth came from "a war zone deep inside Chechnya" and had lived there during the ugly war with the Russians. He also says Tsarnaev was "a wonderful kid" and "nothing in his character" suggested the carnage he’s accused of.

I was in Chechnya briefly during the first modern Chechen war with the Russians in 1995 (the Russians launched a second war in 1999). This might offer some clues.

I flew in on a Russian military transport plane with shell-shocked Russian nurses and doctors who were still reeling from duty on the front lines.

Chechens, a Muslim mountain people, have been fighting Russian imperial, then Soviet and then Russian-again overlords for centuries for independence. The battles have been vicious. The Chechens give no quarter and neither do the Russians. When I Chechnya, I watched from a Russian base overlooking the Chechen capital of Grozny as Russian heavy artillery fired non-stop for hours into 8 and 10-story civilian apartment buildings below. Grozny was ultimately flattened. I later drove through Chechen villages, just ahead of Russian helicopter gunships that were bombing the villages behind me.

Vladimir Putin has held on to Chechnya, fearing the emergence of an independent Chechen Islamic republic just south of Russian’s underbelly, which contains several republics largely populated by diverse ethnic groups that practice the Muslim religion. Putin installed a brutal Chechen ally and warlord, Ramzan Kadyrov, to head the republic, who has kept the rebellion under control.

But Chechen hatreds fester, and Chechen fighters have joined jihadis in Afghanistan and elsewhere. Tsarnaev, who, says Aaronson, came to this country as a boy "six or seven years ago" was too young to have been present during the Chechen wars of the 1990s but surely knew there history. And no doubt they affected his family. At some point we will learn whether this history fed into the madness that apparently drove him and his brother to commit terrible crimes.