BTW if I felt like putting on my conspiracy theorist hat, I think the worst possible case for the Boston bombings is if the bombers were not, in fact, Muslim radicals, but were acting on behalf of the Russian government in an attempt to get the US to crack down on Chechnya.
Conspiracy or not, though, I am pretty concerned about Russia using this as an excuse to invade Chechnya again. Because if history's told us anything, Russia really fucking loves invading the Caucasus and it's been like five years since the last time they did.