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

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?

Read more: Iran terror blast highlights success – and growing risk – of ISIS-K regional strategy

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 country in 2021. Although that pressure has continued under Taliban rule, ISIS-K has grown in strength in recent years, with several thousand fighters now operating in almost every one of Afghanistan’s 34 provinces.

If ISIS-K is indeed responsible for the Moscow attack, we should prepare for further attempted attacks – not just in Russia but across Europe.

European authorities have arrested ISIS-K operatives on multiple occasions. After years of warnings that Islamic State was rebuilding the capacity and resolve to resume an international terrorist campaign, Friday’s attack shows the threat is immediate and substantial.

Read more: A string of assassinations in Afghanistan point to ISIS-K resurgence – and US officials warn of possible attacks on American interests in next 6 months

Earlier this month, the US, together with five other nations, had shared intelligence they had of ISIS-K planning for attacks in Moscow. But these warnings were, as recently as last week, rejected by President Vladimir Putin and the Kremlin as being part of an attempt to discredit Russia.

The attack comes at the worst possible moment for Russia’s despotic leader, in the wake of his successful “election campaign” to claim a mandate for a further six years in power.

And it is perhaps for this reason that Putin’s five-minute televised address on Saturday, in which he directed blame toward Ukraine, came so late.

We don’t yet know whether the Kremlin will continue to blame Ukraine or the West for the attack, or if it will pivot to accept Islamic State was responsible.

Either way, it’s likely to respond with a wave of violence, cracking down on Russia’s Muslim minority communities in the North Caucasus region and beyond.

Why would they target Russia?

Both Islamic State in general, and ISIS-K in particular, have long proclaimed their intention of striking Russia.

They have cited Russia’s earlier military occupation of Afghanistan in the 1980s and its long history of crackdowns on Muslim communities in Russia, particularly in the North Caucasus. They have also cited Russia’s role in providing a lifeline to the brutal regime of Bashar al-Assad in Syria.

But it was also likely opportunity and personnel that led the group to select a soft target in Moscow, as much as anything else.