How Did a Global Jihad Network Take Root in Nationalist Palestinian Camps?

For those of you who read the interesting New York Times article about the infiltration of Palestinian refugee camps in Lebanon by global jihadist groups with ideological ties to Al-Qaeda will find the following report by Bernard Rougier interesting. While these camps were previously hotbeds of Palestinian nationalism, hosting groups such as Fatah and even leftist groups such as the PFLP and DFLP, the internal politics of Lebanon makes it impossible for Lebanese security forces to enter the camp which makes these autonomous entities within Lebanon an ideal refuge for Jihadists.