I am more than sympathetic to the desire of American Muslims to put as much distance as they can between themselves and the Tsarnaev brothers. We Jews know only too well what it is like to be blamed collectively for things we didn’t do, beginning with the crucifixion of Jesus.
But when a Jew does something terrible, we do not get to pretend that he is not one of us. For example, as much we may abhor the behavior of Baruch Goldstein, who gunned down dozens of Muslim worshipers at the Shrine of the Patriarchs in 1994, we cannot deny that he belonged to the people of Israel. Such is the nature of Jewish ethno-religious identity.
Muslim identity seems different. Responses when a Muslim kills innocent people tend to be that the perpetrators are not real Muslims or are heretics, that people like that do not merit Muslim burial rites, that the true Islam is embodied in Koranic injunctions against such killing.
I’m afraid that this approach, understandable as it is, essentializes Islam in a way that plays into the hands of Islamophobes. The latter, selecting their own proof texts, picture a uniformly negative religion that is simply the mirror image of what the apologists portray.
Better, I think, to acknowledge that faith traditions with centuries of history, complex scriptures, diverse and mutually antagonistic sub-groups, and millions of followers encompass examples of the worst as well as the best that humanity has to offer. To own the worst as well as the best is to put your enemies in a position of having to recognize the best as well as the worst.