Beginning in the mid-1990s under the regime of President Boris Yeltsin and continuing into the early part of the 2000s under Vladimir Putin, Russia fought a so-called "dirty war" against Chechen separatists in a region of the world that military strategists have long considered among the most indomitable. Even in Afghanistan, where many Chechen fighters went to train in Taliban-run training camps, they had a reputation for ferocity that frightened many war-hardened Afghans.
As the younger brother, 19-year-old Dzhokhar Tsarnaev, who is the surviving suspect in the Boston marathon bombings six days ago remained silent and in serious condition in a Boston hospital, and apparently did not issue any public statement about motives, it is impossible to say why — if indeed it was him and his brother — they did it. So what follows is speculation.
We know that older brother Tamerlan — the name of the famous 15th-century Central Asian conqueror — visited relatives in Chechnya for about six months in 2012, according to his father, in order to renew his Russian passport. Authorities are currently investigating the possibility that he connected with radical separatist groups during his visit. He posted videos by radical jihadi figures to YouTube when he returned.