Once more, Iran's collusion with al-Qaeda has come to the fore after a United Nations (UN) report named Saif al-Adel, a high-ranking al-Qaeda official believed to be located in Iran, as the operating and uncontested leader of the group.
After al-Qaeda's former leader Ayman al-Zawahiri was killed in a US drone strike last July in Afghanistan, the group never recognised his death, nor did it officially name a successor.
Al-Adel, a former Egyptian special forces officer and close affiliate of Osama bin Laden with a $10 million bounty on his head, is not officially recognised as the leader, according to the United Nations (UN).
Most UN member states suspected that a "key factor" behind al-Qaeda's silence is the continued presence of al-Adel in largely Shia Iran, the UN report reads.
"This raised difficult theological and operational questions" for al-Qaeda, which has long viewed Shia Muslims as apostates, The Washington Post reported.
"Our assessment aligns with that of the UN -- that al-Qaeda's new de facto leader Saif al-Adel is based in Iran," a US State Department spokesperson said on February 15.
The UN report said that the predominant view of member states is that al-Adel is now the group's leader, "representing continuity for now".
Unsurprisingly, the office of the Islamic Republic's UN representative has denied al-Adel's presence in Iran.
The report has stated that another reason al-Qaeda has not formally declared al-Adel as its leader is out of sensitivity to the concerns of Afghan officials, who have not acknowledged that al-Zawahiri was killed in Kabul last year.
"His location raises questions that have a bearing on al-Qaeda's ambitions to assert leadership of a global movement in the face of challenges from ISIS ['Islamic State of Iraq and Syria']," the UN report noted.
Why Shia Iran?
After joining the Islamic Jihad in Egypt in the 1980s, al-Adel was arrested and then released, ending up in Afghanistan and joining al-Qaeda.
According to the Counter-Extremism Project (CEP), he was arrested in Iran in 2003 and freed in 2015 in a prisoner exchange. He was still suspected of being in Iran in 2018 as one of al-Zawahiri's key deputies.
"Saif is one of the most experienced professional soldiers in the worldwide jihadi movement, and his body bears the scars of battle," according to a profile of the alleged terror group leader written by counter-terrorism expert Ali Soufan.
"When he acts, he does so with ruthless efficiency," Soufan wrote in a 2021 article for the CTC Sentinel, published by the Combating Terrorism Centre at the US Military Academy.
Al-Adel's apparent continued presence in Iran is a sign of pragmatism, Soufan said.
"Despite the hateful necessity of living under Shia rule, al-Adel's best chance of survival, and therefore of continued effectiveness in the jihad, lay in a return to Iran," he said.
Iran's Shia rulers officially oppose al-Qaeda, yet Iran has been accused repeatedly of co-operating with the network and giving sanctuary to its leaders.
For CEP director Hans-Jakob Schindler, al-Adel "is a liability but also an asset for the Iranian regime".
According to its interests, Tehran could decide to hand him over to the United States, or allow him to attack the West.
Of Iran's ties with al-Qaeda in 2017, then-US Central Intelligence Agency (CIA) director Mike Pompeo said, "There have been relationships, there are connections. There have been times the Iranians have worked alongside al-Qaeda."
Past assessments by the US Treasury and State departments have repeatedly stated that the Iranian regime allows al-Qaeda to maintain a "core facilitation pipeline" on its soil.
History of harbouring terrorists
The relationship between al-Qaeda and Iran began during the era when bin Laden was the group's leader, according to Nabil Naeem, a founding member of the Islamic Jihad in Egypt who has renounced extremism.
That relationship has continued after bin Laden's death, he told Al-Mashareq in 2018.
In 2020, al-Qaeda's second-in-command Abdullah Ahmad Abdullah -- aka Abu Mohammed al-Masri -- was killed in Tehran by Israeli agents.
Iranian officials reportedly protected him in an upscale suburb of Tehran for years.
Al-Masri, indicted in the United States in connection with charges in the 1998 co-ordinated bombings of its embassies in Tanzania and Kenya, was shot and killed in Tehran in the summer of 2020 by clandestine Israeli operatives on a motorcycle at Washington's behest, The New York Times reported in November of that year.
Al-Masri was one of al-Qaeda's founding leaders and was thought to be first in line to lead the organisation after al-Zawahiri.
In Iran, al-Masri mentored Hamza bin Laden (Osama bin Laden's son), who was being groomed to take over the organisation, according to terrorism specialists.
Hamza was killed in 2019 in a counter-terrorism operation in the Afghanistan-Pakistan region.
A cache of documents recovered in 2017 from Osama bin Laden's compound in Abbottabad, Pakistan, further suggests that the Iranian regime, in particular the Islamic Revolutionary Guard Corps (IRGC), has strong ties with al-Qaeda.
The IRGC is alleged to have hosted a large number of al-Qaeda elements on the run from international authorities.
Maj. Gen. Qassem Soleimani, the then-commander of the IRGC's elite Quds Force who was killed in Baghdad in January 2020, was "the architect of the relationship between the IRGC and al-Qaeda", according to Naeem.
Before he was killed in Syria in 2008, Hizbullah military commander Imad Mughniyeh also "played an important role in training [al-Qaeda] elements, particularly on the methods of booby-trapping and bombing", he added.
Al-Qaeda's relationship with both the IRGC and Iranian intelligence is strong, he said, noting that "the symbolism of the relationship was manifest when Iran hosted the family of al-Qaeda leader Osama bin Laden".
Both sides have been stoking sectarian tensions for years, Naeem said, with "the IRGC portraying itself as protecting the rights of Shia and defending them, and al-Qaeda using the same tactic with the Sunni community".
Iran has consistently denied housing al-Qaeda officials, but with the latest revelations, that party line is becoming harder to believe.
"Iran uses sectarianism as a cudgel when it suits the regime, but is also willing to overlook the Sunni-Shia divide when it suits Iranian interests," Colin P. Clarke, a counter-terrorism analyst at the Soufan Centre, told The New York Times.