Why the Islamic State threat to Iran is growing

On 3 January, two explosions erupted at a ceremony commemorating the anniversary of the death of Islamic Revolutionary Guard Corps (IRGC) Quds Forces commander Qassem Soleimani.

Eighty-four people perished and the south-eastern city of Kerman was rocked by the most devastating terrorist attack on Iran since the 1979 Iranian Revolution. Islamic State- Khorasan Province (IS-K), a terrorist organisation that primarily operates in Afghanistan, swiftly claimed credit for the attack.

Since the attack on Kerman, Iran has stepped up its crackdown on alleged IS suspects and struck what it claimed were IS targets in Syria’s Idlib Governorate. These actions are unlikely to defuse the IS threat to Iran, which has incrementally grown since IRGC forces clashed with IS forces during the Syrian civil war.

As Afghanistan remains the most significant nexus for IS coordination against Iran, the Kerman attack is likely to further intensify Tehran’s diplomatic pressure on the Taliban to rein in IS-K.

"IS-K's presence in Afghanistan poses the most significant terrorism threat to Iran"

Iran's response to the IS attack in Kerman

Although IS-K swiftly admitted responsibility for the Kerman attack, Iran was careful not to single out the group as the perpetrator. Ayatollah Ali Khamenei vowed retribution for the Kerman attack, stating “cruel criminals must know that they will be strongly dealt with from now on,” but did not assign blame for the explosions.

The IRGC extolled Soleimani’s courage and described the Kerman attack as a “blind and malicious act” aimed at fomenting insecurity within Iran. 

Once IS-K’s culpability was confirmed, Iranian media outlets promoted conspiracies about Israeli involvement in the Kerman attack. Ayatollah Seyyed Ahmad Alamulhadi’s commentary on the Kerman attacks, which claimed that Israel financed it to prevent an Iranian retaliation, featured in the state-owned ISNA outlet.

Mona Hojat Ansari, a Tehran Times commentator, declared “Israel played an undeniable role in orchestrating the terrorist attack by at least giving orders and providing logistics”. This aligns with Iran’s long-standing track record of linking IS attacks in Syria to Israel’s strikes on Iran-linked military assets.

While Iran’s official and state-aligned media outlets deflected from the IS threat, the Iranian authorities have taken legal action against suspected terrorists. On 11 January, Iran’s Ministry of Intelligence confirmed that it had identified a Tajik national named Abdollah Tajiki as the main suspect in the Kerman bombings.

Tajiki had crossed the Tajikistan-Iran border in mid-December 2023 and allegedly planted bombs before fleeing two days ahead of the Soleimani memorial. Iran’s Ministry of Intelligence concurrently claimed that it had arrested 35 people in relation to the Kerman attack.

Iran has also used a mixture of diplomacy and military force to demonstrate its resolve against the IS threat. On 8 January, Iran’s Special Envoy for Afghanistan Hassan Kazemi Qomi met with the Taliban’s Deputy Prime Minister for Political Affairs Mohammed Abdul Kabir.

After their meeting, Qomi pledged not to support anti-Taliban forces in Afghanistan and Kabir emphasised Afghanistan’s solidarity with Iran against the IS threat. On 15 January, Iran fired nine missiles on Idlib and the IRGC linked these attacks to mitigating the IS threat. Iran’s plans to upgrade military-technical cooperation with Russia could also address IS, as both countries are wary of IS-K’s spillover into Central Asia.

The scale of the threat to Iran

While the Kerman attack was unprecedented in scope by historical standards, it reflects the years-long expansion of the IS threat to Iran. As IS made sweeping territorial gains in Iraq in 2014, Iranian officials and state media outlets downplayed the danger that it posed.

In a June 2014 statement, Iran’s Deputy Foreign Minister Hossein Amirabdollahian claimed that IS posed “no threat against the geographical borders of the Islamic Republic of Iran”.

Iran’s fears that IS would eventually establish a foothold near the Iraq-Iran border and its desire to legitimise military support for Syrian President Bashar al-Assad caused it to sharpen its focus on IS.

In response to calls to massacre Shias, Iranian officials highlighted the need to protect Shia shrines in Syria from “Wahhabi terrorists”. With the backing of Assad’s army and the Russian special forces, the IRGC expelled IS from Palmyra in March 2017. This triumph became an integral part of Soleimani’s legacy. In May 2020, Mehr News described him as the “shatterer of ISIS” and mocked US President Donald Trump as a “whiny wimp” for taking credit for IS’s demise.

"Iran is likely to strengthen its overall relationship with Afghanistan to ensure that the Taliban remains a useful security partner against IS-K"

Even though IS’s territorial holdings in Iraq and Syria were largely eliminated, it continued to pose a homeland security threat to Iran. In June 2017, IS claimed an attack on the Iranian Parliament and Ayatollah Khomeini’s mausoleum, which resulted in the deaths of 12 people.

In October 2022, IS took credit for an attack on the Shahcheragh Shrine in the southern Iranian city of Shiraz, which killed 15 people. This shrine was attacked again in August 2023, as IS-K killed 13 people in an apparent retaliation for Iran’s execution of two of its operatives.

These attacks have encouraged Iran to step up its counterterrorism efforts. In September 2023, Iran’s Ministry of Intelligence claimed it arrested 28 IS terrorists and thwarted 30 prospective attacks by carrying out raids in Tehran, Alborz, and West Azerbaijan. This reflected Iran’s fears that IS would carry out a retaliatory terrorist attack on the first anniversary of the death of Kurdish women’s rights campaigner Mahsa Amini.

In December 2023, the IRGC staged a large-scale anti-IS drill near Qasr e-Shirin, which is located near the Iran-Iraq border, that included drones, helicopters and armoured vehicles.

These drills mirrored its October 2021 exercises near Azerbaijan, which were ostensibly aimed at stemming IS near its northern border and reflected the determination of Iranian authorities to show that they had the IS threat under control.

How Iran will address the IS threat in Afghanistan

IS-K’s presence in Afghanistan poses the most significant terrorism threat to Iran. Even though Iran welcomed the US’s withdrawal from Afghanistan and has cultivated close diplomatic ties with the Taliban for nearly two decades, it has expressed frustrations with the Taliban’s handling of the IS-K threat.

After Taliban spokesperson Zabiullah Mujahid claimed that IS was largely contained in April 2023, Iranian media outlets highlighted the Taliban’s history of downplaying the IS-K threat. These sentiments soon entered Iran’s diplomatic discourse. In July 2023, Amirabdollahian claimed that IS leaders from Syria, Libya and Iraq had taken refuge in Afghanistan.

This statement was rebuked by the Taliban, which claimed that it “meticulously fought” against IS-K. In September 2023, Iran’s Intelligence Minister Sayeed Esmail Khatib softened Amirabdollaian’s position by highlighting effective Iran-Afghanistan cooperation against IS-K but still reiterated that militants had moved from Syria and Turkey to northern Afghanistan.

Despite its frustrations with the Taliban’s handling of IS-K, Iran is disinclined to address the threat through military means. The Helmand River water-sharing dispute, which resulted in armed clashes between Iran and Afghanistan in May 2023, has also reached an informal diplomatic resolution.

This further reduces the risk of Iran replicating its unilateral strikes on Iraqi Kurdistan’s capital of Erbil and Idlib in Afghanistan. The Taliban’s December 2023 dismantling of what it called an “important network” of IS-K affiliates near the Iran-Afghanistan border underscored its desire to combat the group without Iranian interference.

Given these dynamics, Iran is likely to strengthen its overall relationship with Afghanistan to ensure that the Taliban remains a useful security partner against IS-K. The November 2023 arrival of a 30-member Taliban “economic delegation” to Tehran underscored Iran’s ability to offer Afghanistan sanctions-proof economic cooperation.

"With large-scale military action off the table, Iran is likely to use diplomacy, military exercises, and domestic repression to prevent a repetition of the Kerman terrorist attack"

In tandem with discussions on agriculture, infrastructure, and the status of Afghan migrants in Iran, Taliban First Deputy Prime Minister for Economic Affairs Mullah Abdul Ghani Baradar held talks with Iran’s Supreme National Security Council Ali-Akbar Ahmadian. These discussions likely addressed the IS-K threat, as Baradar claimed that “Afghanistan will not pose a threat to any of its neighbours”. 

Four years after Soleimani’s assassination, the legacy of his anti-IS crusade lives on and poses an ongoing terrorism threat to Iran. With large-scale military action off the table, Iran is likely to use diplomacy, military exercises, and domestic repression to prevent a repetition of the Kerman terrorist attack.

Samuel Ramani is a tutor of politics and international relations at the University of Oxford, where he received a doctorate in 2021. His research focuses on Russian foreign policy towards the Middle East

Follow him on Twitter: @SamRamani2