The capture of the second of the two suspected Boston Marathon bombers ends one of the most extraordinary manhunts in American history. But it brings us no closer to understanding why the crime was committed.

The father of Djokhar and Tamerlan Tsarnaev said in Dagestan, a Russian republic,  that he believed that his sons were set up. This is a logical reaction for a person from Russia where conspiracy theories are generally a reaction to real conspiracies. As applied to the U.S., however, it makes little sense.

In the face of the overwhelming evidence against the two men, the real question is whether the bombing was in some way related to the Chechen conflict or whether the Tsarnaev brothers were “lone wolves.

On the basis of extremely limited information, it appears that the brothers were lone wolves or jihadis recruited by radical extremists but without a direct relation to Chechnya. In the first place acts of Chechen nationalist terror have been directed against Russia, which waged two ruthless wars in Chechnya that claimed anywhere from 80,000 to 200,000 lives. The U.S. had little role in these conflicts.

At the same time, the two brothers fit the psychological profile of newly minted fanatics. They were both seemingly normal albeit relatively unsuccessful young people who had little contact with their peers and began to exhibit signs of religious extremism.

President Obama in his remarks at the memorial service for the victims of the bombings assured the world that Boston and the U.S. were undaunted and would not be defeated by terrorists. This superfluous observation was jarringly inappropriate in light of the fate of the victims whose lives are gone regardless of whether Boston or the U.S. return to normal life. The resort to indiscriminate murder on the part of two seemingly ordinary and Americanized young men, moreover, demonstrates that the virus of murderous fanaticism can break out anywhere and will continue to claim victims unless it is confronted at all levels, intellectual, police, and military and crushed once and for all.   

David Satter is affiliated with the Hudson Institute, Johns Hopkins University and the Foreign Policy Research Institute in Philadelphia. His latest book, It Was a Long Time Ago and It Never Happened Anyway: Russia and the Communist Past, has just been released in paperback by the Yale University Press.