The world's largest humanitarian operation in the western Sudanese region of Darfur is on the verge of collapse due to escalating violence, a United Nations humanitarian official warned on Monday (August 28). "Insecurity is at its highest level since 2004, access at its lowest levels since that date and we may well be on the brink of a return to all-out war," the Emergency Relief Coordinator and Under-Secretary-General for Humanitarian Affairs, Jan Egeland, told the UN Security Council on Monday.