Vahid Hosseini struggled to make it in the United States after he left Iran 25 years ago. A trained engineer, he hauled trash, delivered pizza and worked in landscaping.

Then, in 2008, Hosseini found a more lucrative activity: buying industrial equipment from dozens of American companies and shipping it to Dubai, from where it was forwarded to Iran.

Hosseini said in an interview he knew he was violating U.S. economic sanctions against his home country but thought of it as a minor infraction. "You think that is OK," Hosseini, 64, said at his Virginia home, where he is serving the remainder of a 30-month prison sentence after being transferred from a halfway house in December. "I was thinking that I am 5 miles (8 kph) over the speed limit."