Tom Cotton, Chair of the Senate Intelligence Committee, has said that Americans are “right” to be worried about the prospect of Iranian sleeper cells posing a threat from within the United States as the country threatens retaliation for the bombing of its nuclear facilities over the weekend.
President Donald Trump gave the go-ahead on Saturday night for the bombing of three sites being used by Iran to enrich uranium, allegedly with a view to developing a nuclear weapon, as the U.S. belatedly joined Israel’s Operation Rising Lion offensive.
Speaking to Brian Kilmeade on Fox News’s Fox and Friends on Monday morning, Cotton, an Alabama Republican, was confronted with Customs and Border Protection figures claiming that Joe Biden’s preceding administration had allowed 729 Iranian nationals into the country between 2021 and 2025.

Asked by Kilmeade if the public had “a right to be concerned,” Cotton answered: “Unfortunately, they do have a right to be concerned.
“Joe Biden had a wide-open border policy for four years. We know that terrorists tried to enter our country. Iran has a long history of terrorizing America, going back 46 years to include here in the United States.
“They tried to assassinate Donald Trump last year. Someone finally answered the call to Iran’s fatwa against Salman Rushdie a few years back and brutally stabbed him.”
Cotton went on to stress that Iran had not suddenly become “a terrorist state” because of Trump’s actions and that the president had no choice but to act because Iran “cannot be allowed to have nuclear weapons.”
His comments followed similar remarks made by Vice President JD Vance on NBC’s Meet the Press on Sunday, when he, too, blamed the Biden administration for allowing “crazy people” into the country and pledged to do everything possible to keep Americans safe.
Sleeper cells consist of spies or terrorists living undercover in a foreign country who remain inactive and often lead quiet, unassuming lives, working regular jobs, until their home state orders them to act upon a given mission.
Cotton and Vance’s warnings come as the National Terrorism Advisory System issued a bulletin cautioning that a “heightened threat environment” now exists in the U.S. as a result of Trump’s decision to proceed with Operation Midnight Hammer, which targeted Iran’s the Fordow, Natanz, and Esfahan facilities with “bunker buster” bombs.

The bulletin does not outline specific threats but does warn that “low-level cyber attacks against U.S. networks by pro-Iranian hacktivists are likely, and cyber actors affiliated with the Iranian government may conduct attacks against U.S. networks.”
It states that law enforcement “has disrupted multiple potentially lethal Iranian-backed plots in the United States since 2020.” It warns, “the ongoing Israel-Iran conflict could also motivate violent extremists and hate crime perpetrators seeking to attack targets.”
The bulletin adds: “The likelihood of violent extremists in the homeland independently mobilizing to violence in response to the conflict would likely increase if Iranian leadership issued a religious ruling calling for retaliatory violence against the United States.”
In a statement of her own, Homeland Security Secretary Kristi Noem said: “It is our duty to keep the nation safe and informed, especially during times of conflict.
“The ongoing Israel-Iran conflict brings the possibility of increased threat to the homeland in the form of possible cyberattacks, acts of violence, and antisemitic hate crimes.”
A worldwide caution alert has also been issued for the benefit of American travellers overseas.