Mousa Mohammed Abu Marzook was born in Rafa in the Gaza Strip in 1951.Studied engineering at Ein Shams University in Cairo and graduated in 1977. He worked as manager of a factory in the United Arab Emirates (UAE) until 1981. In 1981, Marzook moved to the United States to pursue higher education. He earned a Ph.D. degree in Industrial Engineering in 1991. While living in the United States in the 1980s and early 1990s, Marzook was reported to have lectured to a training session of terror recruits at a June 1990 conference in Kansas. While in the United States, he served as the political director of the Springfield Virginia-based United Association for Studies and Research (UASR). The UASR has been linked to two Palestinian-Americans who were arrested in Israel for bringing funds into the country to organize Hamas terror activities.
Marzook was then elected as Chairman of the Hamas Political Bureau in 1991 and shortly after moved to Jordan, where he lived for three years. While in Jordan he is suspected of planning numerous terrorist attacks, including the April 1994 bombings in Afula and Hadera. In 1995, he was arrested in the United States at New York's JFK Airport after returning from a trip from the Middle East. Israel requested he be extradited to Israel on charges of issuing commands and transferring money to the military wing of Hamas. Israel later decided not to pursue the extradition request and he was deported to Jordan. Marzook was deported from Jordan in 1999 in response to a Jordanian crackdown on Hamas. He is believed to be traveling on a Yemeni passport and residing in Syria.