WASHINGTON—Federal law-enforcement officials are on high alert for domestic retaliation in response to the U.S. bombing in Iran, warning of potential Tehran-backed plots and cyberattacks. Federal Bureau of Investigation officials in cities including New York,

Few people inside the administration knew the president was moving forward with plans for the attack, even late last week.

President Donald Trump said Israel was going to “turn around” its jets and stop attacking Iran and their ceasefire was “in effect” on Tuesday after briefly faltering. “ISRAEL is not going to attack Iran.