WASHINGTON (Reuters) - President Barack Obama's July 2011 date for the start of a U.S. exit from Afghanistan is a calculated risk with two goals: to remind the Kabul government that support has limits and to reassure war skeptics at home.
Analysts saw major perils for Obama should his plan fail to show results within the 18 months, given the huge challenges U.S. and NATO forces face in Afghanistan.
Breaking sharply from his predecessor President George W. Bush who resisted withdrawal timelines for Iraq, Obama said on Tuesday his revamped strategy that includes 30,000 additional troops would "allow us to begin the transfer of our forces out of Afghanistan in July of 2011."
"It's a big gamble. It's probably the biggest gamble of the whole speech and the strategy," said Bruce Riedel, a former CIA analyst who chaired Obama's review of his Afghanistan policy in March of this year.
"In 18 months we will know whether this strategy is working ... We will either have broken the momentum of the Taliban ... or not," said Riedel, now at the Brookings Institution.
Republicans, many of whom welcomed the troop increase, pounced on the 18-month timeline, saying any explicit goals for a withdrawal would embolden Taliban and al Qaeda militants to wait the United States out.
Riedel said if there is progress within the 18 months, U.S. forces could begin transferring responsibility for security to the Afghans. If not, the strategy would likely call for a "radical course change."
"It's just unrealistic to expect literally miracles in 18 months," said Rutgers University political scientist Ross Baker. "This is not a country that's even as advanced as Iraq.
"It's not a modern country in the sense that Iraq is a modern country. I think the problems of overcoming corruption, training the military and subduing the Taliban in 18 months is a hugely ambitious and I think is probably an unrealistic ambition."
A senior U.S. official said the timeline aimed in part to inject urgency, not only into the Kabul government but also into the U.S. administration to make the strategy work.
"The president is a big believer in measuring progress," the official said. But he added that nobody expected Afghanistan to be a "perfect place" by July 2011.
"Nor does anyone expect that there will be a precipitous removal of our troops immediately in the wake of this point. This is a transition point," the official added.
Obama's election campaign last year leaned on solid support from antiwar Democrats galvanized by his opposition to the Iraq war. He will need that support again when he runs for re-election in 2012.
More immediately, he faces a tough sell in Congress. The troop increase is expected to cost up to $30 billion and many of Obama's fellow Democrats fear the money could come at the expense of public works and job creation programs.
Deepening skepticism among the American public about the war has reinforced the wariness of Democratic lawmakers.
Baker doubted that the withdrawal deadline would help the war effort but said it could soothe some Democrats' concerns.
But he doubted that setting deadlines was the right way to win wars. "The end of the Cold War didn't come about as the result of a deadline," he said.
While the White House insists domestic politics did not play into the decision to set the target date, analysts said it might reassure Democrats that Afghanistan would not become a Vietnam-like quagmire.
"He probably had no choice. He had to have something that answers the requirement from congressional Democrats to show a timeline for how this all starts to come to end," Riedel said.
Administration officials said July 2011 was not a firm deadline. Rather it was as a time when U.S. forces would begin transferring security responsibility to the Afghan government.
The timeline was needed to keep the pressure on Afghan President Hamid Karzai to tackle corruption and take on more responsibility, they said.
"This is not an open-ended commitment," said White House spokesman Robert Gibbs. "We are going to provide them with the incentives that they need via this transition point, to get their act together, to train that security force and army so that beginning in July 2011, we can transfer the responsibility of Afghan security to the Afghans."
National security expert Rick Nelson, a former Navy helicopter pilot, said the timeline may give Obama some leverage over Karzai's government.
"Certainly with an aggressive strategy like this, there are risks," said Nelson, now with the Center for Strategic and International Studies think tank. He added: "We cannot be in Afghanistan forever."
Additional reporting by Ross Colvin and Patricia Zengerle, editing by Alan Elsner