Something to think about as we learn more in the coming days about both Dzhokhar Tsarnaev and his deceased brother Tamerlan. Everything investigators have released so far suggests that they acted alone, and you can easily find instructions to make the kind of bomb they used on the Internet. But as details get fleshed out about where they went, what they did, and whom they met in the last few years, there's a phrase we'll be hearing a lot: "ties to al-Qaeda." So before people start saying the brothers had "ties to al-Qaeda," we should make sure we know exactly what we're saying when we use that term.
We still don't know much about why the Russian government contacted the FBI regarding Tamerlan, and what he did on an extended trip to Chechnya and Dagestan in 2012. Who knows, maybe Ayman al-Zawahiri himself went to Grozny to meet with him, told him how to make the bombs, and ordered him to carry out the attack. But probably not.
It's a lot more likely that we'll find out about some far more tenuous "ties" (or perhaps "links") of the talked-to-a-guy-who-knew-a-guy-whose-cousin-knew-a-guy variety. But some conservatives aren't even waiting to find that out. Lindsey Graham argued that it was justified to hold Dzhokhar as an enemy combatant "with his radical Islamist ties and the fact that Chechens are all over the world fighting with al-Qaeda." There are those "ties" popping up.
Some people obviously see it in their interest to fit the Tsarnaev brothers neatly into their perception of the worldwide Islamic enemy, and if the only "tie" they can find is that Dzhokhar visited some Islamist web sites, that'll be good enough for them. So it wouldn't hurt if the next time Lindsey Graham or any other politician starts talking about their "ties," any reporters nearby asked to hear exactly what the "ties" consist of. Then we can judge how seriously we ought to take it.