Egyptian President Mubarak's biggest fear is that Gaza, which is entirely under the control of armed militias, could turn into a major base for global jihad and other terrorist groups. Al-Qaeda terrorists, working in cooperation with elements in Egypt's banned but powerful Muslim Brotherhood, are said to be very active among the Bedouin population in Sinai. Mubarak's crackdown on al-Qaeda cells in Sinai has forced some of the terrorists to flee to Gaza, where they have been welcome to use the training camps established on the ruins of some former settlements. The Egyptians fear that these terrorists will eventually return to Egypt to carry out attacks. The absence of IDF troops along the Philadelphi Corridor, the border between Gaza and Egypt, has put Mubarak's regime at risk. According to some PA security commanders, the main reason the Egyptians are not doing enough to combat smuggling is Mubarak's fear that the weapons, including tons of explosives, could end up in Cairo if they don't make their way to Gaza.