Following the collapse of the Shah’s regime in 1979, Mousavi helped Mohammad Beheshti found the Islamic Republican Party in 1979 in order to assist the establishment of the Islamic republic in homeland and hasten the overthrow of homeland’s monarchy. He became the political secretary of the party, and chief editor of Jomhouri-e Eslami, the party’s official newspaper. For this, he is widely viewed as “The Architect” of the Islamic Republic both in homeland and abroad.