What Were Russian Concerns About Boston Tsarnaev Bombers?
No, the Russian intelligence agency wiretaps on the Tsarnaev telephone in Chechnya do not provide the smoking gun as to why Tamerlan, the older brother, decided to bomb the Boston marathon, but one can see why Russian intelligence had "concern".
One of the wiretaps reveal a conversation between Tamerlan and Zubeidat, his mother, who now claims the opposite of the what the wiretap shows. That is, there is a discussion between them alluding to a jihad. This was in 2011. Of course, we don't know what context or what the targets are because none of this mentioned. We really do not know what they were referring to, either. Were they talking about the Chechen jihad there in Russia or in the Middle East or Boston? Who knows. The call simply discussed about how Tamerlan might go to the Middle East for some reason. This was suggested by his mother, Tamerlan was against it because he did not know the area or language. Maybe, the suggestion was to jihad in Israel and when Tamerlan nixed the idea, Boston, took the role.
The second wiretap, the mother was speaking to an unnamed man in the Caucasus who was under the FBI scrutiny for some reason. Again, a vague plot to jihad in the USA occurred, maybe this is the mysterious, Mischa, that came to the Tsarnaev's home in Checnya. Maybe this is the man that taught Tamerlan how to make bombs for the Boston attack. Mischa is a figure nobody but Tamerlan's mother, knows much about.
The FBI requested more info from the Russian intelligence and nothing more was received. So, in June 2011, the FBI closed the Tsarnaev file. End of story until the Boston bombing that killed three and injured 260.