The attack, the deadliest in Russia in years, is a major embarrassment to the Russian leader and happened just days after he cemented his grip on the country for another six years in a vote that followed the harshest crackdown on dissent since the Soviet times.Russian authorities arrested the four men suspected of carrying out the attack on a suburban Moscow concert hall that killed at least 100 people and believe they were headed to Ukraine.Videos posted online showed gunmen in the venue shooting civilians at point-blank range. Why IS attack Moscow while Russia is the only country that is supporting muslims resistsnace agains the west ?

