* Meetings begin Tuesday on Afghanistan strategy
* Multiple opinions among advisers
* Gates could be key voice in deliberations
By Steve Holland
WASHINGTON, Sept 29 (Reuters) - If President Barack Obama decides to send 30,000 to 40,000 more U.S. troops to Afghanistan, he will be doing it against the advice of some advisers and leading Democrats in Congress.
Obama’s national security team launches a series of closed-door meetings on Tuesday to reassess U.S. strategy in Afghanistan. Obama first wants to determine the proper way forward for U.S. forces in Afghanistan before considering whether more troops should be sent.
Any decision is weeks away.
"This isn’t going to be finished in one meeting. It’s not going to be finished in several meetings," said White House spokesman Robert Gibbs.
Some opinions are divided within the administration over whether to bolster forces as Obama moves toward what will be a pivotal decision in a war that his predecessor, George W. Bush, began after the Sept. 11 attacks in 2001.
"The president is going to hear opinions from people he trusts and respects who are likely to be at odds with each other. In the end he has to make the decision," said an administration official who spoke on condition of anonymity.
Obama is in a difficult position. He risks upsetting his liberal base of support by sending more troops but could face questions from critics about "who lost Afghanistan?" should Taliban militants take control of the country again.
U.S. Army General Stanley McChrystal, the top commander in Afghanistan, said in a report to Obama that the eight-year-old war would end in failure without additional troops and changes in strategy aimed at gaining the trust of the Afghan people.
"I’m confident that I will have an absolute chance to provide my assessment and to make my recommendations," McChrystal told CBS "60 Minutes" in an interview broadcast on Sunday.
"VERY DIFFICULT DECISION"
Vice President Joe Biden has proposed a shift in the U.S. mission to concentrate on attacking al Qaeda targets that are primarily in Pakistan, using Predator drone missiles and other tactics, while increasing training of Afghan forces.
"Clearly there are at least some people in the White House who would prefer that," said Stephen Biddle, an Afghanistan expert at the Council on Foreign Relations.
While Secretary of State Hillary Clinton did not tip her hand on where she stands in an interview last week with "Newshour" on PBS, she said it is important to concentrate not just on Pakistan but Afghanistan as well.
"Some people say ‘Well al Qaeda’s no longer in Afghanistan.’ If Afghanistan were taken over by the Taliban, I can’t tell you how fast al Qaeda would be back in Afghanistan," she said.
A critical voice in the deliberations will be Defense Secretary Robert Gates. Gates has made clear in recent days he has yet to decide whether he agrees with McChrystal that more troops should be sent.
Some Democratic leaders in Congress are raising a caution flag against sending large numbers of extra troops, such as Senator Carl Levin, chairman of the Senate Armed Services Committee.
Levin has said he wants to rapidly train Afghan forces with U.S. trainers "without creating a bigger U.S. military footprint that provides propaganda fodder for the Taliban."
A Gallup poll last week said 50 percent of Americans opposed sending more troops to Afghanistan while 41 percent supported it, a drop in backing for the conflict.
"This is not easy and I would expect that the public would ask some very tough questions," Obama said last Friday. "That’s exactly what I’m doing, is asking some very tough questions."
Obama telephoned Senator John McCain, his Republican opponent from last year’s election campaign, on Saturday to get his advice on Afghanistan. McCain supports sending more troops.
"I think he has a very difficult decision," McCain told ABC’s "This Week" on Sunday. "The base of his party, Americans are weary, understandably they’re weary. And it’s a very difficult decision for him. But I believe he’ll make the right decision."
James Dobbins, an Afghanistan expert at the Rand Corporation think tank and veteran of past administrations, said the debate within the Obama team is good for the country, because "if the president does not listen to conflicting views, he denies himself access to information and a full range of choices."
Biddle said it would not be unusual if Obama were to go against the counsel of his military advisers, since that is what Bush did when deciding on a surge of U.S. troops in Iraq that some of his commanders had opposed.
Biddle said he felt McChrystal’s assessment is correct, "but by the same token, I think military assessments need to be carefully evaluated against other voices and ideas." (Additional reporting by Susan Cornwell and Adam Entous; Editing by John O’Callaghan)