Terrorist attack in Moscow exposes Putin's vulnerability. At least 137 people died in the attack, even though the United States had clearly warned on March 7 that an attack on a concert hall could be imminent.
Putin also did not mention the Islamic State, which claimed responsibility for the attack on the Crocus City concert hall on Friday. Four men - Dalerjon Mirzoev, Saidakrami Rachabalizoda, Muhammadsobir Fayzov and Shamsidin Fariduni have been charged with an act of terrorism.