To add a couple of things that are Russia specific:
(1) We now learn that the FBI had interviewed the older brother at the bequest of an unspecific foreign government – almost certainly Russia. Tamerlan had visited it for 6 months in 2011. I wonder if he established links with some of the Caucasus Emirate Wahhabi types while there – and if so, whether US suspicions about Russia’s “assaults” on human rights in Chechnya made them drop their guard on a man who, it is now clear, was by then fast becoming an Islamist radical. The one silver lining to this horrible event is that it will become even more obvious that the Chechen rebellion has now been completely subsumed into the global Islamist struggle – and by extension, it will encourage the West to take a closer look at its “friends” in Syria.
(2) The reactions of Russian liberals has as always been as hilarious as it is nauseating. They seriously believe that the FSB is behind this.
Vasily Gatov, state news agency RIA employee: “I am watching three TV channels and listening to the radio, and reading the Boston Globe, and I gather that the main task of the FBI is to take the suspect alive. There is a drama brewing between Watertown, Washington, Moscow, and Grozny… And who knows which other cities. But I’m sure that the greatest fear is felt in Grozny. Which is why he will be taken alive.“
Self-hating random Echo of Moscow commentator: “I will not be surprised if it turns out that the Tsarnaev brothers where recruited by Russian special forces for the execution of this terrorist act, because Russia will benefit from it. Why? Because this terrorist act will change American and Western public opinion – and hence, that of their politicians - towards Chechnya. If before the Western public supported the Chechens’ independence struggle, it is now more likely that they will support the Russian government’s policy on the Caucasus. And this means that the Kremlin KGBists will be able to use still crueler and more barbaric methods to fight separatism on the part of the Caucasus peoples. In other words, this terrorist act will untie the hands of the Kremlin in its war against the peoples of the Caucasus.“