[3] He studied at the Damascus University where he joined the radical, pro-Syrian Popular Front for the Liberation of Palestine – General Command (PFLP-GC) under Ahmed Jibril in 1968.

Zaidan, who opposed Syrian involvement in the Lebanese war, left the PFLP-GC and created the PLF with Talaat Yaacoub, which eventually split into three separate factions (and then later re-merged).

Since its inception in 1977, the Abbas-led PLF was a member of the Palestine Liberation Organization and received support from both the PLO and Yasser Arafat's Fatah movement.

One notable attack by the PLF under Zaidan's leadership resulted in the deaths of Danny Haran (age 28) and his two daughters, Einat (4) and Yael (2) in April 1979 in their Nahariya, Israel home by Samir Kuntar.

Subsequent to the US invasion of Iraq on 20 March 2003, Zaidan was captured by American Special Forces on 14 April 2003 while he was attempting to flee from Baghdad to Syria.

[citation needed] The U.S. authorities agreed to give Abbas' body to the Palestine Red Crescent Society for burial in Ramallah on the West Bank.