The Wall Street Journal reports on last night’s violence in Watertown, Massachusetts related to the Boston bombings:

U.S. authorities on Friday locked down the Boston area in the hunt for one of two brothers of Chechen background suspected in Monday’s Boston Marathon bombings.

Authorities identified one suspect as 26-year-old Tamerlan Tsarnayev, who was killed in a confrontation with police in Watertown, Mass., according to a U.S. law-enforcement official.

A manhunt was on for the second suspect, identified as Dzhokhar Tsarnayev, 19 years old. Both brothers were believed to be involved in the fatal shooting of a Massachusetts Institute of Technology campus police officer during a chaotic series of events Thursday night.

CBS reports that there is no evidence of connections between the two men and any terrorist groups in the North Caucasus:

There has been no indication that the Tsarnaev brothers are linked to Chechen terror groups operating in the region now. The former head of the school who spoke to the Reuters news agency in Dagestan said the whole family left for the U.S. in 2002.

So what to make of this? Based on initial reports, it appears that this was an attack launched by two brothers whose religious and political views were radicalized in part by their experience of fleeing their home because of the Chechen wars and partly through their sympathy with and interest in jihadist propaganda online. According to Haaretz, the younger Tsarnaev’s website expressed his identification with Islam and Chechen independence. Why they would choose the marathon of all things as their target isn’t entirely clear, but presumably it offered them an opportunity to harm as many people at once as possible in a high-profile way. What they hoped to achieve beyond notoriety and mayhem isn’t known, but perhaps that was enough for them.

I think Jacob Heilbrunn gets this wrong:

So the two suspected bombers—if suspect will even be the operative word later this day—are Chechens. Nothing illustrates the hollowness, the grandstanding of American foreign policy better than the fact that America has antagonized the one country that might have been able to help avert the blasts in Boston [bold mine-DL].

When our own law enforcement and intelligence agencies were completely unaware of a plot unfolding here in the U.S., it seems doubtful that Russia would have been able to alert us to these specific attackers when these men have been outside Russia for over a decade. Cooperation with Russia in counter-terrorism is valuable, and as a general rule I think antagonizing Russia is a pointless and destructive way to handle the relationship. However, I don’t see how Russian cooperation would have made any difference in this case. Russian help might be useful in determining whether or not there are any links between the Tsarnaevs and some group in the North Caucasus, but for now there wouldn’t appear to be any obvious implications for Russia policy here.

As for the “vindication of Putin,” I don’t think that holds up very well, either. Russian policy in the North Caucasus has been and remains brutal and repressive, and the Kremlin’s brutality contributed to transforming what was originally a separatist struggle into a jihadist cause. Insofar as the second Chechen war contributed to the Tsarnaevs’ willingness to engage in terrorism, the Boston bombings are a delayed form of blowback from Putin’s war. Obviously, none of that excuses the atrocities that Chechen terrorists have carried out over the years, but it is important to remember this in order to understand why Chechnya became a magnet for jihadists and why Chechens driven out of the region would be drawn to jihadism. In the case of the Tsarnaevs, it appears that the Chechen wars may be part of the explanation for their radicalization, but they are not the whole story.

Update: Here is some additional useful background on the Tsarnaevs.