The terrorist attack in Moscow claimed by the Islamic State-Khorasan is Russia's worst nightmare come true. After Chechen separatism, which was responsible for horrific terrorist attacks in Russia from the late 1990s into the first decade of the new century, the threat of an attack by the IS has loomed large over Russia for nearly a decade. In 2015, the Islamic State of Iraq and the Levant (ISIL) claimed the mid-air explosion of a Russian chartered flight that was headed from the Sharm al Sheikh airport to Moscow, killing all 217 passengers and seven crew. The IS has had Moscow in its sights ever since Russia provided military assistance to the Bashar al Assad regime in Syria, helping the regime to retrieve territory from ISIL, which contributed to the terrorist group's eventual decline in the region. As IS found a new pasture in Afghanistan, it started out with a mix of ethnic groups, including disgruntled lower-rung Taliban fighters resentful of their leaders' peace talks with the Americans, as well as Uyghurs, Uzbeks and others. But Central Asian recruits have dominated the IS-K since the Taliban's dramatic return to Kabul and a consolidation of Pashtun power. Concerns about IS-style radicalisation and terrorism via Central Asia have dominated Russia's, and indeed the Central Asian Republics', engagement with the Taliban since 2021.