Senior Palestinian Hamas leaders Mahmud Zahar and Mussa Abu Marzuq (back) attend a conference in Tehran in support of Gaza and Palestinians on March 4, 2009. Iran's supreme leader Ayatollah Ali Khamenei called for world Muslims to join the Palestinian "resistance" against Israel as he kicked off the summit in aid of war-torn Gaza. AFP PHOTO/BEHROUZ MEHRI (Photo credit should read BEHROUZ MEHRI/AFP/Getty Images)