The war with Iran has defense experts wondering if Khamenei will attempt to activate sleeper cells on U.S. soil

“We know where most of them are. We got our eye on all of them, I think,” President Trump told the world media this week. The commander in chief was speaking about the possibility of Iranian sleeper cells being embedded and activated in the United States.

The concept of sleeper cells—groups of organised, foreign spies living unremarkable lives until directed into action—may, in the public imagination, feel like something from the movies or the pages of a book. The same goes for lone wolves, individuals who operate without direct command or support from a larger organization.

The president speaking to this threat on the tarmac in front of Air Force One crystallized the long-held reality for defense and counterterrorism experts. Sources who spoke to Fortune are of the opinion that, out of sheer desperation, the Iranian regime may search for a way to damage the U.S., Israel, or their allies, in a bid for retribution.

The Islamic state’s losses are significant: The U.S. said it had targeted the nation’s ballistic missile strikes, navy ships and submarines, and command and control centers. As Trump puts it, “there’s practically nothing left” to target. More than 1,400 Iranians have died, according to casualties calculated by Al Jazeera. An ongoing military investigation has also determined that faulty U.S. targeting data resulted in a deadly Tomahawk strike on a girls’ elementary school, instead of a nearby military base.

The U.S. and Israel, motivated to action by national security fears, have lost 26, according to Al Jazeera at the time of writing. Trump has claimed the Iranian regime has tried to assassinate him twice, with Defense Secretary Pete Hegseth adding the U.S. has been aware “for a long time” that the Iranian regime is targeting high-ranking U.S. officials. Experts told Fortune that Iran and the U.S. have long targeted each other—and fundamentally do not understand each other.

Wilbur Ross, President Trump’s former commerce secretary, told Fortune that while it’s “very hard to imagine” that Iran will be able to rebuild as a major geopolitical threat, factions within the nation might “resort to activating whatever sleeper cells they have in various countries, including the U.S., to do one-off things, maybe something like the World Trade Center.” Even the suggestion to attempt another 9/11 would shake intelligence and defense departments across the globe.

Sleeper cells in the American imagination

While some defense experts maintain sleeper cells have long been embedded in U.S. society, Reuel Marc Gerecht argued the notion is “probably a bit dated.” Gerecht, a former Iranian targets officer at the Central Intelligence Agency (CIA) who now works for the Foundation for the Defense of Democracies, told Fortune that if sleeper cells existed, they would have been activated in the past. More likely, he explained, is that the Iranian regime may rely on foreign criminal networks—as demonstrated by the attempted murder of human rights activist Masih Alinejad, using two Russian criminals in Brooklyn in 2022—to target individual dissidents.

“We don’t need to worry about deep-cover Iranian sleeper cells like you might see in Hollywood,” echoed Michael Rubin, a former Pentagon official, now a senior fellow at the American Enterprise Institute, where he specializes in Iran and the broader Middle East. “When the Iranians operate in the United States, they often operate by tapping into existing criminal networks.”

This week, reports surfaced that the FBI had sent a memo to California police departments saying it had acquired unverified information that Iran may attempt to launch drone strikes on the West Coast. White House press secretary Karoline Leavitt highlighted that the intelligence was unproven, writing on X: “No such threat from Iran to our homeland exists, and it never did.” A White House official said the entire administration is closely monitoring all intelligence, and is vigilant in deterring any potential threats should they arise.

Rubin, who spent time with the Taliban researching the organization prior to 9/11, is more concerned about “innocuous blackmail” of individuals being coerced into logistically aiding foreign powers. Gerecht believes lone wolves pose more danger, arguing their isolation from existing networks means law enforcement sometimes relies on luck to identify the threat. “I would be willing to bet money that all the usual suspects are being looked at now,” Gerecht added. “Whether they maintain that surveillance for how long, that’s a different issue.”

Iran’s brain drain

In a military sense, the U.S. campaign in Iran is going as well as anyone could expect, observed Secretary Ross. Michael Allen, managing director of Beacon Global Strategies, is inclined to agree, saying the counterterrorism strategy for the U.S. is to “keep a boot on [the Iranian regime’s] throat, so that they’re unable to do anything other than figure out how to survive, instead of thinking about how to pull off complex external attacks on the West.”

Allen, who worked in the White House for eight years on the National Security Council and the Homeland Security Council, told Fortune: “I can’t ever rule it out … so I’m not saying that everything’s been eraticated, but … the strategy has to be with these issues to keep smothering it, to keep it down as much as possible.”

Having worked its way through high-priority targets, reports are emerging that the U.S. is now striking police stations. The infrastructure disarray comes on top of what Gerecht referred to as a “brain drain” in Iran. “If you don’t start with a decent bench, you’re not gonna make the bench better,” Gerecht said. “It’s one thing to want to do something and then it’s another to be able to do something.”

Wary but not panicked

The Iranian state knows it cannot “win” a war with the U.S. So its strategy is likely to escalate costs for the U.S. and its allies, forcing them to cease hostilities, thus leaving the regime in place.

“I think it’s consistent with [the state’s] strategy to try and launch something,” said Allen. “Their overall strategy is, of course, to survive, to kill Americans … but all for the purpose of forcing the United States to say: ‘You know what, the costs have gotten too high.'” 

Reports that the Iranian regime had begun attacking its neighboring states means it has burned some bridges, added the sources, indirectly helping the U.S. “keep everyone on side and rowing in the same direction,” noted Allen. “It indirectly helps the U.S., especially in the medium to long term.”

“The Iranian regime is always searching for revenge,” added Gerecht. “That was true before the American-Israeli air raids, and it’s just as true today.”

A question of context

The complexity of the Iranian nation has historically made it difficult for most foreign intelligence agencies to embed themselves there. Iran has five institutional languages compared to the U.S.’s one; three language families have given rise to more than 60 dialects. Moreover, though the exact makeup of Iran’s demographics is hard to decipher, in 2022 the country’s government undertook a headcount of undocumented Afghan nationals, of which 2.6 million were registered.

Israel’s intelligence-gathering in the Middle East is strong, the sources told Fortune, though Rubin argued that the analysis of this data may have created blind spots. Rubin, who previously taught at the Hebrew University in Jerusalem, observed that intelligence gathering by Israel in Iran was, at first, built on the skills of immigrants who settled in the country from across the world: “The Israeli intelligence service had a granularity where they would understand the dialect of a local neighborhood, and would be able to understand on a street-by-street level how something works, allowing them to penetrate and also allowing them to understand these societies.”

However, a generation on, Rubin suggests that Israel’s experience in conflict with Arab communities has largely been with Palestine: “Without knowing it, [Israel] tends to filter all their understanding of Iran … through the Palestinians, but the Arabs aren’t monoliths—nor is the Middle East a monolith.”

This story was originally featured on Fortune.com