RAMALLAH, West Bank: Fatah s one-time Gaza strongman Mohammed Dahlan quit as national security advisor on Thursday more than a month after Hamas smashed Palestinian security forces and captured the Gaza Strip. Dahlan submitted his resignation to president Mahmoud Abbas at the request of a commission appointed to investigate failings in the security services, which were defeated in Gaza on June 15 after a week of deadly fighting. The commission recommended his dismissal or resignation and he has chosen to resign to the immediate acceptance of President Abbas, said an official at the presidency in the West Bank political capital of Ramallah. The 45-year-old Fatah MP and former Gaza strongman was appointed national security advisor on March 18, but in practice had vacated the job since Abbas dissolved the Palestinian national security council on June 18. Detested by Hamas, he is a former minister of internal security and one-time chief of Gaza s powerful preventive security force. Some within Fatah hold Dahlan responsible for the security services defeat at the hands of the Islamist fighters in Gaza, and he has spent the past month in Egypt for what is expected to be a lengthy barren spell. Seen as one of the closest US allies in the Palestinian Authority, he is a leading figure in the young guard of top Fatah officials – Hebrew-speaking men who grew up in the territories under Israeli occupation after 1967. Hamas heavily criticized Dahlan s appointment as national security advisor, accusing him of trying to organize a coup within Fatah and of trying to assassinate sacked Hamas Prime Minister Ismail Haniya. Always impeccably dressed in elegant suits, Dahlan cultivated a dynamic image as a young, modern and efficient official. His fluent Hebrew, learnt in prison, proved an asset on the Palestinian negotiating team in various peace talks with Israel. Born in 1961 to a Gaza refugee family, Dahlan became a member of Arafat s Fatah movement, going on to lead its youth wing, the Shabiba, in the West Bank. He was very active in the first Palestinian intifada (1987-1993) as student leader. He was in and out of Israeli jails between 1981 and late 1986, before being deported to Jordan in 1988. He later joined the Palestine Liberation Organization (PLO) in Tunis where he won Arafat s confidence. Dahlan returned to the Gaza Strip in 1994 at the launch of self-rule after the 1993 Oslo accords to become the head of the preventive security forces as part as Arafat s Palestinian Authority. During his seven years in the job, he was heavily criticized by human rights groups for the methods used to crack down on Islamic militants, and he was also dogged by corruption allegations.