WASHINGTON (Reuters) - Leaked documents on the Afghanistan conflict, including accusations that U.S. ally Pakistan is helping the Taliban, further complicate President Barack Obama's strategy at a time of mounting doubt over the war effort.
While Pakistan's covert support for the Taliban has been reported for years, experts say that revelations about this support contained in documents made available by online whistle-blower WikiLeaks add to existing skepticism over the efficacy of the U.S. engagement with Pakistan.
"The documents underscore the depth of Pakistani support (for the Taliban) and frustrations within the American military about that," said former CIA analyst Bruce Riedel, now with the Brookings Institution, a Washington think tank.
"This definitely makes it more complicated for the Obama administration," added Riedel, who led a White House review of Afghanistan and Pakistan policy early last year.
But Riedel said the bottom line was that the United States has no choice but to work with Pakistan even if revelations such as those made by WikiLeaks make it tougher to retain U.S. congressional and public support for the effort.
The 91,000 secret documents detail events in the war between 2004 and December 2009. That was the month when Obama announced a new counterinsurgency strategy and troop surge intended to turn around the war that began in 2001 in retaliation for the September 11 attacks on the United States.
But critics of the war may cite the documents as evidence that the U.S. war strategy will fail even with the 30,000 additional troops Obama last December ordered to Afghanistan.
"These WikiLeaks should not be used to say the strategy is doomed to failure," said Lisa Curtis of the conservative Heritage Foundation think tank. "It is too early to say that."
Curtis said part of the problem in sustaining U.S. public support for the war is that the Obama administration's message is "very confused."
"They need to stop talking about a timeline. It disheartens our allies and encourages the enemy," she said, referring to Obama's pledge -- criticized by many U.S. conservatives -- to start pulling out U.S. troops by July 2011.
Afghanistan expert Anthony Cordesman said the timing of the leaks rather than their content may be the most damaging aspect for the White House, as Obama's team seeks to change what media experts call an increasingly gloomy war "narrative."
"The president has a messaging problem," said Cordesman of the Center for Strategic and International Studies think tank.
Fighting in the Kandahar region -- the Taliban's stronghold -- has been tougher than expected, casualties are on the rise and the White House is still reeling from the fallout from the firing of war commander General Stanley McChrystal last month.
U.S. lawmakers also have been raising more questions about the war effort and its goals. Obama is under pressure to show progress in time for a planned policy review in December that will look at whether additional troops have made a difference.
This sour mood has not been helped by comments from experts such as Richard Haass, a former State Department official and current Council on Foreign Relations president who suggested last week that the war is not worthwhile.
"This administration has not yet clarified its core goals and the end state. Many Americans, particularly congressmen, are asking: how does this end?" said Brian Katulis with the Center for American Progress think tank.
"You are seeing some stirrings of opposition, but as yet I don't see the architecture shaping up for a concerted anti-war effort," Katulis said.
The White House is also sensitive ahead of the November U.S. congressional elections in which Obama's fellow Democrats are trying to prevent the opposition Republicans from regaining control of Congress.
So far, the Afghanistan war has drawn little interest on the campaign trail, with most of the focus on U.S. unemployment and the Gulf of Mexico oil spill.
Katulis and others said it was unlikely that fallout from the WikiLeaks disclosures will provoke the same anti-war mood that undercut President George W. Bush's Republican Party in 2006 congressional elections when the Iraq war was going very badly.
But analysts suggested that Obama talk more often about his reasons for being in Afghanistan and seek to reassure Americans that the war is worthwhile, especially during an economic downturn.
"The president has chosen to speak very rarely about this issue. As it gets more contentious, he will have to come out and articulate why he is doing what he does," Riedel said.
"It remains a mystery to me why the White House does not have a better strategy of articulating what our goals and objectives are."
Editing by Will Dunham