Influential US experts on Friday painted a grim picture of the Afghanistan war, calling on President Barack Obama to consider scaling back the military mission without signs of progress.
The task force of the Council on Foreign Relations largely backed the Obama administration's plan of intensifying military operations against the Taliban and starting a withdrawal in mid-2011.
But the panel -- led by Richard Armitage and Samuel Berger, top aides to presidents George W. Bush and Bill Clinton -- said the administration needed to take hard decisions after its own highly anticipated war review in December.
The task force noted the nine-year-old war's toll at a time of austerity. The United States has some 100,000 troops stationed in Afghanistan and is spending billions of dollars in the region each month.
"The task force endorses strategies for Pakistan and Afghanistan that place severe demands on the American people," it said. "The task force does so knowing that, at best, the margin for US victory is likely to be slim."
"If progress is being made, the United States should be able to draw down its forces starting in July 2011, based on conditions on the ground," it said.
"However, if US efforts are not working, a more significant drawdown to a narrower mission that emphasizes counterterror objectives with fewer US forces will be warranted," it said.
Some 10,000 to 20,000 US troops led by Special Operations Forces would fight militants, the study said, noting that most Al-Qaeda camps in Afghanistan have already been eliminated since the September 11, 2001 attacks.
But the task force said that such a strategy also came with major risks, particularly if the Taliban teamed up with international terrorists to fight a weak central authority in Afghanistan.
"Under those circumstances, Afghanistan could easily fracture into full-fledged civil war. That war would be every bit as devastating as earlier Afghan conflicts, creating millions of refugees and widespread humanitarian tragedy," it said.
"By its decision to remain focused on a narrow counterterror mission, the United States would be held partly to blame for the suffering, making many Afghans even less willing to assist US operations," it said.
However, the task force said a more focused mission could help the United States with the ultimate solution in Afghanistan -- a political settlement that brings some Taliban into the mainstream.
A smaller force would also reduce US dependence on supply routes in Pakistan, reducing the neighboring country's leverage, the report said.
The task force faulted Pakistan's security services, saying that despite offensives against some homegrown extremists, "Pakistan has not made a decisive break with all militants on its territory, especially those active against India and Afghanistan."
But the study endorsed the Obama administration's pursuit of closer ties with Pakistan, including last year's 7.5-billion-dollar civilian aid package, saying it was crucial to encourage stability in the nuclear-armed nation.
The task force called on the United States to give greater market access to Pakistan's textiles. But it warned against talking to Pakistan about civilian nuclear cooperation, saying it would be counter-productive to give false hopes for a deal that stands little chance of approval by Congress.
The task force involved 25 scholars, although some dissented from the findings.
Opinion polls have shown growing US opposition to the Afghanistan war. However leaders of the Republican Party -- which swept congressional elections last week -- have pressed Obama to drop the mid-2011 timeline, saying it only encourages the Taliban to wait for a US withdrawal.
The Obama administration has appeared to shift emphasis away from the drawdown, instead stressing the goal of handing over security to Afghans by 2014.
Defense Secretary Robert Gates, on a visit this week to Australia, said that the upcoming NATO summit in Lisbon would aim to endorse the 2014 target.
The gradual transition was likely a "years-long process" that would begin in some areas next year as Afghan forces steadily expand and improve, Gates said.