By Kanishka SinghWASHINGTON, Jan 28 (Reuters) – A Brooklyn man was sentenced to 15 years in prison on Wednesday for taking part in what prosecutors called a failed Iran-backed murder-for-hire plot against Masih Alinejad, a prominent Iranian dissident living in the U.S., the Justice Department said. Alinejad, who fled Iran in 2009, is a longtime critic of Iran’s head-covering laws and a journalist. She was living in Brooklyn at the time of the alleged plot on her life. The case was part of a crackdown by the Justice Department on what it calls transnational repression: the targeting by authoritarian governments of political opponents on foreign soil. Other people have also been convicted in the U.S. and sentenced in relation to the alleged plot.