WASHINGTON — The Department of Homeland Security is warning of a ''heightened threat environment'' following U.S. strikes on Iranian nuclear sites and the deputy FBI director says the bureau's ''assets are fully engaged" to prevent retaliatory violence, while local law enforcement agencies in major cities like New York say they're on high alert.
No credible threats to the homeland have surfaced publicly in the days since the stealth American attack. It's also unclear what bearing a potential ceasefire announced Monday by the U.S. between Israel and Iran might have on potential threats or how lasting such an arrangement might be.
But the potential for reprisal is no idle concern given the steps Iran is accused of having taken in recent years to target political figures on U.S. soil. Iranian-backed hackers have also launched cyberattacks against U.S. targets in recent years.
The U.S. has alleged that Iran's most common tactic over the past decade, rather than planning mass violence, has been murder-for-hire plots in which government officials recruit operatives — including reputed Russian mobsters and other non-Iranians — to kill public officials and dissidents. The plots, which Tehran has repeatedly denied engineering, have been consistently stymied and exposed by the FBI and Justice Department.
''You run into this problem that it's not like there's this one sleeper cell that's connected directly to command central in Iran. There's a lot of cut-outs and middlemen,'' said Ilan Berman, a senior vice president of the Washington-based American Foreign Policy Council. ''The competence erodes three layers down.''
Whether Iran intends to resort to that familiar method or has the capacity or ambition to successfully carry off a large-scale attack is unclear, but the government may feel a need to demonstrate to its people that it has not surrendered, said Jon Alterman, a Middle East expert at the Center for Strategic and International Studies.
''The capability to execute successfully is different from the capability to try," he said. ''Showing you're not afraid to do this may be 90% part of the goal.''
Hours after the attack on Saturday evening U.S. time, FBI and DHS officials convened a call with local law enforcement to update them on the threat landscape, said Michael Masters, who participated in it as founding director of Secure Community Network, a Jewish security organization that tracks Iranian threats.