Pakistan must be central to U.S. policy on Afghanistan and needs up to $50 billion over the next five years to avoid an economic meltdown that risks turning the country over to Islamic extremists, said a report released. The report by a think tank with close ties to the Obama administration said Washington must also act to strengthen civilian government in Pakistan and persuade Islamabad to stop using militant groups as an instrument of foreign policy. The Asia Society, whose chairman was Richard Holbrooke until he was appointed U.S. special envoy on Afghanistan and Pakistan in January, convened a task force to compile the report: "Back from the Brink? A Strategy for Stabilizing Afghanistan-Pakistan." The report, made public on Thursday, was provided to President Barack Obama's administration before he unveiled his strategy on Afghanistan last week. It closely mirrors Obama's policy, while focusing more on politics than military issues. The report said the global economic crisis risked further weakening Pakistan's civilian government, which has little control over tribal areas that have become safe havens for al Qaeda, and which struggles to match the sway of the military. "Perhaps the most urgent priority is to prevent economic collapse, which could undermine state authority even in major urban areas in the next few months," the report said.