Are Terrorist Sleeper Cells Resurfacing?

Western Intelligence Agencies Are Quietly Mobilizing Against Them

Talking about terror sleeper cells may seem kind of passé in 2025. Do we remember how the notion of these secret cells struck fear in American hearts during the post 9/11 era?

Well, I don’t want to burst your bubble, but it appears sleeper cells are back.

Over the past year, it appears that Western intelligence agencies have been quietly mobilizing their assets and warning local authorities about the prospect that their countries may be facing serious, new terror attacks from embedded terror sleeper cells – cells that currently live quiet lives in our societies.

According to the highly regarded Combatting Terrorism Center, a part of West Point, it turns out that this summer American counterintelligence officials began advising state and local governments “to be vigilant for potential domestic plots in the United States.”

Matthew Levitt writing for the Center warns that, “The 12-day Iran war may be over, but the threat of Iranian reprisal attacks now looms large and will for the foreseeable future.”

It’s not just in Europe, where national intelligence forces have broken up a number of Iranian-organized sleeper cells. Levitt adds that, “Iranian operatives or their agent could also attempt to carry out attacks inside the United States, leveraging what U.S. counterterrorism officials have describe as a ‘homeland option’ developed over years.”

The Homeland Option. Do we have to consider that again?

NBC News additionally reported that after the U.S. unleashed air strikes against Iranian nuclear sites, the FBI reassigned additional counterterrorism agents to work on possible Iranian sleeper cells.

And several days ago, the Mossad, Israel’s intelligence agency, added to the Center’s analysis by issuing a warning that throughout Europe, Iran has activated its transnational terror network against Jews and Israelis.

Israel News over the weekend reported, “A transnational terror network run by Iran’s Islamic Revolutionary Guard Corps (IRGC) Quds Force is behind a string of recent attacks on Jewish sites in Western countries, the Mossad intelligence agency said on Sunday.”

The Mossad reported that the terror attacks throughout the world were led by Sardar Ammar, who heads the IRCG. Ammar commands 11,000 operatives who carry out covert operations, according to the Mossad.

Iranian organized terror attacks have been ongoing throughout Europe and particularly in Australia, where the Canberra government has taken stern measures against Iran’s mullahs.

Australia has directly blamed Iran for its involvement in two highly publicized 2024 arson attacks against Jewish sites, including a synagogue. According to Australia’s prime minister, Iran used criminals and members of organized crime gangs to carry out the attacks.

After it publicized the terror attacks, the Australian government expelled Iran’s ambassador and severed diplomatic ties with Tehran. It was the first time the country expelled an ambassador since WWII.

After the expulsion, Australia also designated the IRGC as a terror organization.

The International Centre for Counter-Terrorism, a think tank based in The Hague, Netherlands reported late last year that British “MI5 Director General Ken McCallum revealed that since January 2022, authorities contended with twenty Iranian-backed plots targeting UK citizens and residents.”

In Germany, relations with the Iranian mullahs have reached an all-time low after numerous terror attacks were reportedly organized by the Islamic Centre Hamburg.

A Bavarian government report described the center as a hub of Iranian terror attacks throughout Europe. An Iranian resistance group wrote this year, saying, “A damning new intelligence report released by the Bavarian Office for the Protection of the Constitution (Verfassungsschutz Bayern) has exposed the Iranian regime’s extensive use of state terrorism, espionage, and proxy operatives across Europe—especially Germany—while identifying the now-banned Islamic Centre Hamburg as the regime’s central propaganda hub on the continent.”

Other terror cells were intercepted by Greece’s anti-terrorism police and arrested seven people, including two Iranians, charging them with arson attacks in Athens.

Thomas Baker, who served for 33 years in the FBI and was posted overseas for the bureau, in part on counterterror assignments, told me the Iranians prefer the use of non-Muslims who would be regarded as “lone wolves.”

“In the past, the Iranians had their overseas terrorism in the developed countries like the United States, they’ve always used proxies,” the former FBI official told me in an interview.

This was confirmed by Australian Security Intelligence Organization chief Mike Burgess after the expulsion of the Iranian ambassador. “They’re just using cut-outs, including people who are criminals and members of organized crime gangs to do their bidding or direct their bidding,” the intelligence agency official told reporters.

He said that the IRGC had “used a complex web of proxies to hide its involvement” in the attacks.

German intelligence officials have confirmed that the IRGC hired a German Iranian Hells Angels gang to organize terrorist attacks in Germany.=

Baker calls the IRGC a “shadow government.”

“They are very powerful, very linked into the religious leaders. And they are the ones we believe are directing violence,” the former FBI official told me.

As is well known, attacks by single individuals against American Jews vastly escalated this year. All are regarded in the media as “lone wolves,” or people who don’t appear to be associated with an organized terror group.

The spate of attacks included the firebombing of the Pennsylvania’s governor’s home on Passover where the Jewish state leader that evening led a Passover seder.

Then there’s the case of a young couple leaving an event at a Jewish museum in Washington, D.C. who were brutally gunned down.

And more than two dozen Jews in Boulder, Colorado who regularly walked to highlight hostages held by Hamas were victims of a firebombing by an Egyptian.

One woman, age 82, died of burns a month after the attack. In all, there were 29 victims. Mohamed Sabry Soliman, a 45-year-old Egyptian citizen was charged with first degree murder. He cried out “kill all Zionist people” while throwing Molotov cocktails.

There also is a concern that actual Hamas terror operatives may be living in the United States. Last week we learned the FBI arrested Mahmoud Amin Ya’qub al-Muhtadi, a Hamas terror operative who led terror attacks on Israelis on October 7, 2023.

Al-Muhtadi was charged with conspiracy to provide material support to a terror organization resulting in death and fraud and misuse of visa permits.

The Biden administration permitted him to enter the United States. When he was arrested, he was quietly living in Lafayette, Louisiana.

After his arrest U.S. Attorney General Pam Bondi issued a statement that said in part, “After hiding out in the United States, this monster has been found and charged with participating in the atrocities of October 7.”

In just the past five years, U.S. authorities have disrupted at least 17 Iranian plots in the U.S., including those involving Iranian operatives as well as terrorist and criminal proxies, according to the West Point center.

And official U.S. Customs and Border Protection statistics show that border interceptions of “terrorist-related encounters” ending in September 2025, was 3,066, a six-fold increase from 2024.

J. Michael Waller, who is a Senior Analyst for Strategy at the Center for Security Policy told me that we need to take a closer look at pro-Iranian mosques in this country. ““We should be looking into certain mosques that show loyalty to the Iranian government. But because they are places of worship, we can’t touch them.”

Waller says former FBI Director Robert Mueller is largely to blame for ending the bureau’s surveillance of the most radical mosques in the United States. Mueller served as FBI Director from 2001 to 2013.

“Before and immediately after 9/11, the FBI was looking at the right places. Then after 9/11 you had this chorus of people who said, ‘oh, that’s bigoted. That’s racist. They’re picking on innocent Muslim people. They’re going after Mosques,” Waller told me.

“What those terrorist supporters found out was that if you apply enough political pressure, and call it racist and bigoted, then you can get the FBI off your back. And it’s exactly what happened under FBI Director Meuller,” Waller said.

This is confirmed by Baker who authored a book detailing the demise of bureau investigations titled, The Fall of the FBI. “Muller let his guard down and in the interests of what some people would characterize it, he embraced the Muslim community. Specifically, he had training manuals changed, and the radical extremism term was expunged,” he told me.

Mueller’s naivete was most evident when he decided to speak at a fundraiser held by the now-defunct American Muslim Council which was founded by Abdul Rahman al-Almoudi.

Al-Almoudi eventually was convicted of a plot, financed by the Libyan leader Muammar Qaddafi, to have then-Saudi Crown Prince Abdullah killed by two Britain-based al-Qaeda operatives. He was sentenced to 23 years in federal prison and stripped of his citizenship.

Ryan Mauro, who follows extremist groups in the United States says that the Iranians and other Islamic Jihad groups have many political supporters in the United States, principally among hard-core Marxists and anti-Israel activists.

We’ve seen many of them at pro-Palestinian rallies and on college campus “encampments” throughout the United States.

“What Iran does have is numbers--legions of terror supporters that are far too numerous for law enforcement to identify, monitor, investigate and prosecute” says Mauro, who is an investigative researcher for the Capital Research Center in Washington, D.C.

“If Iran is able to throw enough darts at the dart board, eventually some will strike,” he told me.

Today, FBI Director Kash Patel and deputy director Dan Bonginoare are trying to reverse the decades of FBI indifference towards militant Iranian mullahs and their followers.

Baker says he hopes the new leadership can change the culture at the bureau. “I hope the new management gets us back to a law enforcement culture. And that’s what I believe we have to get back to,” he told me.

Waller thinks the new FBI leadership is working “as best as they possibly can.” But the years of neglect in this area will take a lot of time to reverse.