"Unraveling the Moscow Attacks: Putin's Response and Suspects' Online Links"
Russian President Vladimir Putin dismissed U.S. warnings of extremist attacks in Moscow as "provocative" and "outright blackmail," only to have a rampage at a Moscow concert hall leave at least 137 people dead days later. The Islamic State group claimed responsibility for the shooting, which the U.S. had reportedly collected intelligence on. Four men have been charged in the attacks, with concerns raised over their confessions.