First, the Iranian government was accused of trying to lure a journalist and dissident from New York City to Turkey to abduct and imprison her. Then, according to U.S. officials, intelligence agents schemed unsuccessfully to kidnap the woman, Masih Alinejad.

In 2022 came the most audacious attempt to silence Ms. Alinejad, who was born in Iran and has long criticized its government. Prosecutors said figures connected to the Islamic Revolutionary Guard Corps of Iran sent members of the Russian mob to kill her.

The plot, authorities say, was thwarted when police officers stopped an Azerbaijani man who had lurked outside Ms. Alinejad’s Brooklyn home and tried to open her door. In his sport utility vehicle, they found an assault rifle with an obliterated serial number, 66 rounds of ammunition and a ski mask.

The men accused of directing the activity in Brooklyn, Rafat Amirov and Polad Omarov, are to stand trial in Federal District Court in Manhattan on Monday, charged with murder for hire and conspiracy. The trial is expected to illustrate the lengths to which Iranian officials will go to retaliate against expatriates, even those living in Western countries, who speak up against the government in Tehran.

“We will not tolerate attempts by a foreign power to threaten, silence or harm Americans,” Merrick B. Garland, the attorney general at the time, said in 2023 when federal officials first detailed the plot against Ms. Alinejad.

Prosecutors are planning to describe how Mr. Amirov and Mr. Omarov operated within a rivalrous, faction-ridden criminal organization known as the Thieves-in-Law, which originated in Stalinist prison camps.