CHICAGO: US President Barack Obama opened a NATO summit Sunday saying the world backed his plan to end war in Afghanistan, as President Hamid Karzai pledged his bloodied state would no longer be a “burden.” Leaders of more than 50 nations stood in solemn silence as a bugler’s lament recalled the heavy cost of a conflict that has killed over 3,000 coalition soldiers, maimed thousands more and left tens of thousands of Afghans dead. As war weary western publics pine for an exit, the summit was set to endorse a withdrawal strategy and seek firm commitments from alliance states to train and bankroll Afghan forces to ensure a decade of sacrifice is not wasted. Obama, fresh from corralling European leaders to unite behind a plan to save the euro at the G8 summit, switched to commander-in-chief in talks with Karzai ahead of the summit, three weeks after his dramatic flight into Kabul