What did Vladimir Putin Know, and When did he Know it?

In September 1999, Vladimir Putin was catching hell for horrific human rights abuses in Chechnya.  Then two apartment buildings were blown up in Moscow, and Putin blamed it on the Chechen separatists, who denied involvement.  Opposition to Putin’s policies vanished, and he was able to launch a massive invasion of Chechnya.  When Alexander Litvinenko began publicizing accusations that Putin was complicit in the Moscow apartment bombings (alleging that FBS operatives had been caught red-handed trying to bomb a third building in Ryazan), Litvinenko was murdered with polonium poison.

Fast forward to April 2013.  Bombs go off during the Boston Marathon and a pair of Chechen terrorists turn out to be responsible. This occurs just as Putin was catching hell for supporting the homicidal dictator of Syria, and seeking to justify his support by claiming that Chechen terrorists were among the rebels fighting to end the dictatorship.  Just as in 1999, Putin attempts to use the bombing to justify his policy, claiming it proves he was right about the Chechens all along.

Then came a blockbuster revelation:  Putin had a wiretap on the Chechen terrorists who bombed the Marathon, and never told U.S. law enforcement about it.  What’s more, Putin began stonewalling the investigation into the bombing, failing to provide lots of other information wanted by U.S. authorities.

Is it possible that Putin knew the Chechens were going to launch an attack on the U.S., and let them do so in order to have convenient justification for his policies in Syria, as well as his crackdown in the Caucasus region?