CAIRO, Egypt (AP) - Muslims worldwide are the main perpetrators of terrorism, a humiliating and painful truth that must be acknowledged, a prominent Arab writer and television executive wrote Saturday, as Middle East media and officials expressed horror at the bloody rebel siege of a Russian school. Unusually forthright self-criticism followed the end of the hostage crisis, along with warnings that such actions inflict more damage to the image of Islam than all its enemies could hope. Arab leaders and Muslim clerics denounced the school seizure as unjustifiable and expressed their sympathy. Russian commandos stormed the school Friday in Beslan,...