During a recent visit to Tajikistan, Russian Federal Security Service Director Alexander Bortnikov claimed that around 5,000 militants based in Afghanistan from a group known as Islamic State Khorasan, or IS-K, had been redeployed to the north of the country, near its border with the former Soviet states of Central Asia.

Bortnikov’s statement has been treated with some scepticism, with Moscow accused of exaggerating the threat posed by IS-K to advance its own objectives in the region. But his comments make it timely to revisit the question of whether IS may emerge as a genuine threat not just to Afghanistan but also to the broader Central Asian region.

To date, the states of Central Asia—Kyrgyzstan, Uzbekistan, Tajikistan, Turkmenistan and Kazakhstan—have been relatively free of terrorist incidents involving Islamist groups. Between 2008 and mid-2018, 19 attacks categorised as terrorism occurred across the region, resulting in around 140 fatalities. Most of these attacks targeted law enforcement agencies, and regional governments have claimed that they disrupted another 61 attacks during 2016 alone.

IS was involved in several of these events. In July 2018, a group claiming allegiance to IS killed four foreign tourists outside of the Tajik capital of Dushanbe, and in November, Tajik authorities claimed that they had detained 12 suspects with alleged ties to IS who were planning an attack against a Russian military base and school.

However, Central Asians have been disproportionately represented among the foreign-fighter cadre of IS in Syria and Iraq. Estimates of the number of IS’s Central Asian foreign fighters range between 3,000 and 5,000. With the collapse of the IS ‘caliphate’, many of these militants may seek to return home. If a broad fatality rate of one-third is applied to this overall figure, that leaves several thousand IS-aligned Central Asian foreign fighters who might try to return home.

The number of Central Asian foreign fighters tells only part of the story of potential support for IS across the region. The Soufan Group’s 2017 report indicated that while around 500 Kazakh nationals successfully travelled to Syria or Iraq, nearly 2,000 were stopped in Turkey. Similarly, around 1,500 Tajiks successfully travelled to IS territory, but around 3,000 were stopped or turned back in Turkey. Figures for interdictions of other Central Asian nationalities aren’t available, but it appears that the 3,000–5,000 Central Asians who made it to IS territory may have been just a small proportion of those who tried to do so. While there’s evidence that some of them may have been radicalised while working in Russia, high-profile cases such as the former head of Tajikistan’s police special operations who became IS’s ‘war minister’ suggest that IS may have broader appeal in Central Asia.

But it’s unclear how many Central Asian foreign fighters will ultimately seek to return to their countries of origin, and, if they do, whether any of them will remain committed to IS. Estimates from 2018 put the total number of returnees at around 300, and a mass return to Central Asia is seen as unlikely due to the repressive nature of the region’s regimes. However, the figure is likely to have increased significantly following the complete collapse of the IS caliphate.

Many of those who have returned have been jailed, creating additional risks of jail-based radicalisation of other inmates. This problem has proven particularly severe in Tajikistan, where prison riots involving IS members in November 2018 resulted in 50 deaths and in late May 2019 around 32 deaths.

More worrying are indications that IS-K is consolidating and expanding its foothold in Afghanistan, and that it may be doing so by drawing on a reservoir of Central Asian militants, including those returning from the Middle East.

Over the past year, IS-K has reportedly made significant ‘tactical gains’ in Afghanistan and has expanded to between 3,000 and 5,000 fighters, up from 600 in 2017. IS-K has specifically targeted Central Asian foreign fighters in the Middle East for recruitment. Afghanistan is a logical destination for those fighters and also for new recruits from Central Asia given its geographic proximity and ethno-linguistic links.

Also, given that IS-K seeks to establish a new caliphate covering South and Central Asia, it’s also logical that it would recruit Central Asians for its Afghan operations, because they can be used to advance the group’s ambitions across the broader region. IS-K has already called for terrorist attacks against public gatherings in Central Asia and has forged allegiances with the Islamic Movement of Uzbekistan and other key Central Asian terrorist groups, building on its connections with the region.

Uzbekistan, Tajikistan and Kyrgyzstan all share a long mountainous border with Afghanistan. If IS-K were to conduct cross-border forays, those countries’ defence and security services would probably struggle to deal with even a small group of battle-hardened, motivated fighters. Tajikistan—which alone shares with Afghanistan a nearly 1,400-kilometre border—would be particularly susceptible to such incursions.

Fortunately, much of this is still in the realm of conjecture. Despite having enjoyed success in Afghanistan over the past year, IS-K will likely take time to consolidate its gains and may not be ready to widen its theatre of operations. Also, despite IS’s rebranding as a global insurgency, it is yet to be seen whether the IS brand has retained its cachet following its defeat in the Middle East. It’s possible that Central Asia’s IS alumni may turn their backs on the organisation and either throw their support behind rival groups such as al-Qaeda, or abandon jihad altogether.

The combination of a hardening of IS-K’s position in Afghanistan and the unresolved question of the intentions of displaced Central Asian foreign fighters creates a wicked security problem for the region. Given the recent spate of IS-inspired attacks in Sri Lanka and Southeast Asia, it may be just a matter of time before Central Asia experiences a mass-casualty terrorist attack. The challenges for local policymakers and for external stakeholders such as Russia, the US and China will be to formulate a strategy that manages these risks without encouraging a clampdown from the region’s security services that ultimately proves self-defeating by driving even more people into the arms of fundamentalists.