After President Trump ordered airstrikes on Iranian nuclear facilities, U.S. officials issued urgent alerts about potential terrorist attacks in the United States, including warnings that Tehran could direct sleeper cells to strike.

But when Iran’s government was determined to assassinate Mr. Trump during the 2024 campaign, it did not activate sleeper agents or try to sneak elite operatives into the country.

Instead, an Iranian military commander assigned the job to Farhad Shakeri, an Afghan man living in Tehran, according to a criminal complaint released by the Justice Department.

Mr. Shakeri in turn enlisted two men he’d met in an American prison more than a decade earlier: Carlisle “Pop” Rivera, a self-employed Brooklyn pipe fitter, and his friend Jonathon Loadholt of Staten Island.

Federal agents detected the plot and arrested Mr. Rivera and Mr. Loadholt.

It was just one of several recent instances in which federal prosecutors say the Iranian government tried to hire criminals — including Russian mobsters, Mexican cartel hit men and a Canadian Hells Angel — to carry out violent acts in the United States.

Iran may be seeking deniability by outsourcing its plots to people with no apparent ties to the country. In January, Iran’s president insisted that his government had never plotted to kill Mr. Trump.