(CNSNews.com) – A U.N. Security Council report this week identified an Iran-based senior al-Qaeda fugitive from U.S. justice as a likely, though not yet confirmed, new leader of the terrorist group.

The report said al-Qaeda’s failure to publicly name Saif al-Adl as successor to Ayman al-Zawahiri was possibly related to his presence in Iran, which raises “difficult theological and operational questions” for the group.

The extent to which the Shi’ite regime in Iran would cooperate with the Sunni jihadists of al-Qaeda has long been debated in security circles, although terror collaboration dating back to the late 1990s has been documented.

State Department spokesman Ned Price said Wednesday the U.S. assessment aligns with the U.N. report’s on al-Adel’s presence in Iran.

“Offering safe haven to al-Qaeda is just another example of Iran’s wide-ranging support for terrorism, its destabilizing activities in the Middle East and beyond,” he said at a briefing

“Are you ready to go after him on Iranian soil?” a reporter asked, noting that the U.S. has targeted previous al-Qaeda leaders, only announcing the operation after the fact.

“We have a commitment that we are prepared to act, and to act decisively, if our people, if our interests come under threat from terrorist groups,” Price replied. “We’ve demonstrated that before in any number of cases, but I’m just not in a position to preview or to speak to the specifics of that.”

Ayman al-Zawahiri was killed in a U.S. drone strike in downtown Kabul last summer, a death which neither al-Qaeda nor the Taliban regime has publicly acknowledged.

“The presence of al-Zawahiri in central Kabul at the time, in a building reported by member-states to belong to the Haqqani Network, demonstrated an ongoing and cooperative relationship between al-Qaeda and the Taliban,” said the U.N. report, which is compiled by a team of experts and based in part on assessments from member-states’ intelligence services.

“Some flagged that al-Zawahiri’s evident presence in Kabul had been an embarrassment for the Taliban, which is seeking legitimacy as a governing authority, and that al-Qaeda chose not to exacerbate this by acknowledging the death,” it said.

While no succession announcement has been made, the report stated, “many member-states took the view that Saif al-Adl is already operating as the de facto and uncontested leader of the group.”

“Assessments varied as to why his leadership had not been declared,” it said, adding that most member-states judged his continued presence in Iran to be “a key factor.”

“This raised difficult theological and operational questions for al-Qaeda,” the report said.

Indicted by a federal grand jury for his role in the 1988 U.S. Embassy bombings in East Africa – in which 224 people, including 12 Americans, were killed – al-Adl is subject to a $10 million U.S. reward offer. Iran has allegedly sheltered him for years.

The U.S. government says the Egyptian national moved to Iran after the 1998 bombings and lived under the protection of the Islamic Revolutionary Guard Corps (IRGC).

With him in Iran was another senior al-Qaeda terrorist indicted for the embassy bombings, Abu Mohammed al-Masri.

Both were placed under house arrest in 2003, but the regime lifted the restrictions in 2015, in exchange for al-Qaeda’s Yemen-based affiliate freeing a kidnapped Iranian diplomat.

Al-Masri was reportedly assassinated in Tehran in mid-2020 – the Iranian regime denied it – but al-Adel is believed still to be in Iran.

“Senior [al-Qaeda] leaders continued to reside in Iran and facilitate terrorist operations from there,” the State Department said in its latest terrorism report, covering 2020.

“Iran remained unwilling to bring to justice senior al-Qaeda (AQ) members residing in the country and has refused to publicly identify members it knows to be living in Iran,” it said.

“Iran has allowed AQ facilitators to operate a core facilitation pipeline through Iran since at least 2009, enabling AQ to move funds and fighters to South Asia and Syria, among other locales.”

Al-Adel (aka Mohammed Salahaldin Abd El Halim Zidane) is a former Egyptian special forces officer whose al-Qaeda involvement in the 1990s included providing training to terrorists in Afghanistan and Pakistan. According to the U.S. government he also trained fighters in Somalia involved in the killing of 18 American troops in Somalia in 1993.

‘Sunni-Shia divisions did not necessarily pose an insurmountable barrier’

Despite skepticism from some about the Shi’ite regime cooperating with Sunni terrorists, reported collusion between Tehran and al-Qaeda go back decades, with Iran’s Lebanese-based proxy Hezbollah playing a key early role.

In his 1999 biography, Bin Laden: The Man Who Declared War on America, Yossef Bodansky recounted meetings attended by Osama bin Laden and Hezbollah’s terrorist chief Imad Mughniyah in Khartoum in 1995 and Tehran in 1996.

Bodansky wrote that at the 1996 meeting in the Iranian capital, a Shi’ite-Sunni “committee of three” was set up to coordinate terror attacks internationally. The three were bin Laden, Mughniyah, and Ahmad Salah of the Egyptian Islamic Jihad, also a Sunni.

The 9/11 Commission report on al-Qaeda’s 2001 attack against America recounted that al-Qaeda operatives traveled to Iran and Hezbollah bases in Lebanon in the 1990s for explosives training.

Bin Laden “reportedly showed particular interest in learning how to use truck bombs such as the one that had killed 241 U.S. Marines in Lebanon in 1983,” it said. “The relationship between al-Qaeda and Iran demonstrated that Sunni-Shia divisions did not necessarily pose an insurmountable barrier to cooperation in terrorist operations.”

“[T]here is strong evidence that Iran facilitated the transit of al Qaeda members into and out of Afghanistan before 9/11, and that some of these were future 9/11 hijackers,” the report said. There was no evidence, however, that Iran was aware of the planning for the 9/11 attacks.

“There is no doubt there is a connection between the Islamic Republic of Iran and al-Qaeda. Period. Full stop,” then-Secretary of State Mike Pompeo told the Senate Foreign Relations Committee in 2019. “The factual question with respect to Iran’s connections to al-Qaeda is very real.”

Despite Sunni-Shi’ite differences, Iran has for years also sponsored Palestinian terrorist groups Hamas and the Palestinian Islamic Jihad.