The internal tension in the Arab cities of Shechem (Nablus) and Jenin in Samaria has long been growing and threatening to boil over, as the Palestinian Authority's (PA) leading Fatah faction and its security apparatus clash. The two cities, which are under full control of the PA as per the 1993 Oslo Accords, in recent days became the scenes of violence between Fatah, which features a "military wing" named the Al-Aqsa Martyrs' Brigade, and the PA Security Forces. An exchange of gunfire was reported last Friday at Jenin between armed men, apparently from Fatah, and members of the PA Security...