Why would Islamic State attack Russia and what does this mean for the terrorism threat globally?

EPA/VASILY PRUDNIKOV by Greg Barton, Deakin University It appears almost certain the brutal assault on a Russian crowd settling down to watch a rock concert in Moscow on Friday night was an Islamist terrorist attack. At least 133 people were left dead and scores more were injured after gunmen with automatic weapons stormed the Crocus City Hall in Moscow and opened fire, triggering a stampede. Islamic State claimed responsibility for the attack, initially through its Amaq media channel and then directly. The modus operandi of the attack also fits with previous Islamic State attacks. It has been widely reported the attack was the work of Islamic State Khorasan (ISIS-K), a branch established in 2015 in Afghanistan. So who is this group, why would they attack Russia and what does this mean for the broader terrorism threat? What is ISIS-K? ISIS-K is the Islamic State branch that has most consistently and energetically attempted terrorist attacks across Europe, including in Russia. ISIS-K has planned some 21 attacks in nine countries in the past year, up from eight the previous year. ISIS-K had been under tremendous pressure from the Afghan Special Forces and American troops before the United States full withdrew from the...