With the Taliban in power in Afghanistan, there’s a new enemy ascending.

The militant Islamic State (IS) group threatens to usher in another violent phase. Except this time, the Taliban play the role of the state, now that the US troops and their allied Afghan government are gone.

The Taliban promised the United States to keep the militant group in check during successive rounds of peace talks. Under the 2020 US-Taliban accord, the Taliban guaranteed that Afghanistan would not become a haven for terrorist groups threatening the US or its allies.

But it is unclear if they can keep their pledge, with a sudden uptick in IS attacks since the Taliban takeover on Aug. 15.

A deadly bombing on Friday in the northern province of Kunduz killed 55 worshippers inside a Shia mosque. Other deadly IS attacks have struck in the capital, Kabul, and provinces to the east and north, while smaller-scale attacks target Taliban fighters almost daily.

“Historically, the majority of IS attacks have targeted the state ... Now that the US and the international presence is mostly gone, they need to go after the state — and the state is the Taliban,” said Andrew Mines, research fellow at Program on Extremism at George Washington University.

Long rivalry

Both the Taliban and IS advocate rule by their radical interpretations of Islamic law. But there are key ideological differences that fuel their hatred of each other.

The Taliban say they are creating an Islamic state in Afghanistan, within the borders of that country.

IS says it is the Islamic State, a global caliphate that it insists all Muslims must support. It is contemptuous of the Taliban’s nationalist goals and doesn’t recognise them as a pure Islamic movement. For similar reasons, IS has long been a staunch enemy of al-Qaeda.

Read more: US wants Taliban, Kabul to jointly combat IS

Both the Taliban and IS advocate particularly harsh versions of Shariah law and have used tactics like suicide bombers. But when it ruled territory in Syria and Iraq, IS was even more brutal and carried out more horrific punishments than the Taliban did.

IS emerged in Afghanistan in 2015 with the name Islamic State in Khorasan Province, at a time when the group was at its peak, controlling much of Iraq and Syria. It drew members from Afghan and militants, including a wave of Taliban defectors.

The group initially found support among Afghanistan's small Salafist movement in eastern Kunar and Nangarhar provinces. The Salafis had largely been marginalised by the Taliban, and by connecting with the rising IS, the Salafist movement found a means to establish military strength.

But IS’s brutal ways have since led some Salafi clerics to voice opposition. In the years after its emergence, IS was badly hurt by military setbacks at the hands of the Taliban and by US airstrikes, before surging again the past year.

The Taliban downplay IS’s capabilities and dismiss them as a fringe group with no mainstream appeal.

“They have no roots here,” influential Taliban figure Sheikh Abdul-Hameed Hamasi told The Associated Press.

End-game

Still, the potency of the IS threat is undeniable.

Two deadly bombings have hit Kabul, including one outside the airport at the height of evacuations before the US exit that killed 169 Afghans and 13 US service members. Smaller-scale attacks are also on the rise.

Also read: Taliban say forces destroy cell of IS hours after Kabul blast

“The intensity and breadth of attacks … show the capacity and level of national reach which has caught the Taliban by surprise,” said Ibraheem Bahiss, a consultant with the International Crisis Group. IS “is no short-term threat.”

It could be a while until IS has the capability to hold territory again. Its immediate aim is to destabilise the Taliban and shatter the group’s image as a guardian of security.

For now, its strategy is slow and methodical. It is reaching out to tribes and other groups to recruit from their ranks while stamping out dissent among moderate Salafis and carrying out jailbreaks, assassinations, and attacks on Taliban personnel.

“Package all of that together, that is an entire method of insurgency the Taliban is not equipped to handle,” said Mines.

Bill Roggio of the Long War Journal, produced by the Foundation for the Defense of Democracies think tank, offered a different view, saying he believes the Taliban can uproot IS on their own, even without the backup of US airstrikes that nearly eliminated IS.

Roggio said the Taliban have shown themselves capable of rooting out some IS cells, using their vast local intelligence-gathering networks.

He noted that IS don't have access to safe havens in Pakistan and Iran.

The Taliban have rejected cooperating with the US against IS, ahead of the two sides’ direct talks last weekend.

IS’s future trajectory in Afghanistan will depend largely on its ability to recruit more members and win over large segments of the population.

Since their inception, they have been poaching Taliban members. In 2015, a former Taliban commander, Abdul Rauf Khadim, was appointed deputy of IS in Afghanistan and reportedly offered financial incentives to other Taliban fighters to join the group.

In 2020, when IS re-emerged in Afghanistan, it was under a new leader drawn from the Haqqani Network, currently a faction of the Taliban.

Hard-line members of the Taliban could join IS as the Taliban leadership, now in power, has to make compromises whether at home or abroad. The Taliban have promised a more inclusive government, though the temporary administration they set up is entirely made up of Taliban members.

The more the Taliban cooperate with international states, the more they run against the image of the mujahedeen resistance fighter. “That is a key identity the Taliban will lose,” Mines said.

Treatment of minorities

As the Taliban shift from insurgency to governance, one key test will be whether they act to protect minority groups that their fighters once tyrannised, such as the Hazaras.

The Hazaras have endured multiple campaigns of persecution and displacement throughout Afghanistan’s history. When the Taliban were first in power in the 1990s, they carried out massacres against the community, in some cases in retaliation for massacres of ethnic Pashtuns.

IS has targeted Hazaras because most are Shias, killing hundreds in brutal attacks targeting their places of worship in what it calls a war on heretics.

Friday’s mosque attack in Kunduz was an opportunity for the Taliban to project a new image as a state power. The Taliban acted swiftly: Special forces swept the scene, investigations were launched, the provincial police chief made lofty promises to protect minority “brothers.”