Prime Minister Manmohan Singh on Thursday called for a total revamp of the UN, including the Security Council, while imploring world leaders to collectively meet the challenges of terrorism, climate change, poverty, HIV/AIDS and energy security. `If we fail the United Nations, we fail succeeding generations, who have every right to expect a more enlightened legacy than is currently in sight,` the Prime Minister told the 60th World Summit of the UN General Assembly in New York. AFP