WASHINGTON (Reuters) - The White House received a letter last year purported to come directly from Mullah Omar, the reclusive leader of the Taliban, asking the United States to deliver militant prisoners whose transfer is now at the heart of the Obama administration's bid to broker peace in Afghanistan.
The unusual message kicked off a debate within the administration about whether it was truly authored by the mysterious one-eyed preacher believed to be directing the Taliban from hiding in Pakistan -- and its meaning for U.S. efforts to forge a negotiated end to America's longest war.
"As we have engaged various interlocutors as part of the reconciliation process, we have received a variety of messages that were represented as being from senior members of the Taliban," an administration official said on condition of anonymity.
"However, we haven't received a letter that we are certain is from Mullah Omar."
The message reportedly expressed impatience that the White House had not yet transferred five former senior Taliban officials out of Guantanamo Bay military prison.
U.S. officials have been considering moving the detainees to Afghan custody in the Gulf state of Qatar as one of a series of good-faith measures that, if successful, could lead to talks on Afghanistan's future between militants and the government of Afghan President Hamid Karzai.
The accelerating efforts to set such talks in motion are a central part of the Obama administration's strategy for leaving behind a modicum of stability as it winds down the U.S. combat mission in Afghanistan.
A former imam and mujahideen guerrilla, Omar has not participated in initial U.S. contacts focused on confidence-building measures. But his public support would be crucial for any peace agreement if substantive negotiations can be had.
After over 10 years of war, Washington and its Western allies are announcing plans to steadily withdraw their troops amid doubts whether the chronically weak, corrupt Afghan government can confront ongoing violence.
The Taliban has been able to survive - indeed flourish in some areas - in part because it has been able to slip across Afghanistan's porous eastern border to rest and rearm.
According to a recent secret report produced by NATO, Taliban detainees in Afghanistan remain convinced they will retake the country when the foreign force of about 130,000 soldiers goes home.
Last month, the Taliban made a surprise announcement it would open a political office in Qatar, suggesting the group may have moderated and would be willing to engage in negotiations that would likely give it government positions or official control over much of its historical southern heartland.
But it is unclear whether the Taliban is truly interested in entertaining authentic political negotiations, or simply wants to recover its prisoners.
The impact of the letter on U.S. reconciliation efforts, headed by Obama's special representative for Afghanistan and Pakistan, Marc Grossman, is likewise uncertain.
The administration official said the Obama administration was "skeptical" the letter was actually from Mullah Omar. "There's no signature. However, it expresses views consistent with what Taliban interlocutors have told us all along."
U.S. officials say no decision has been made to go ahead with the transfer, but the White House is already facing pushback from members of Congress who warn that transferred detainees could rejoin the fight.
While Congress does not have the power to block the move, the White House might rethink such a risky move if serious bipartisan friction emerged in a presidential election year.
Other U.S. politicians note the Taliban may not be prepared to renounce the brutal tactics that characterized its government, which was toppled in the wake of the September 11, 2001, attacks.
The Taliban, which rose to prominence in 1994 under Mullah Omar's leadership, was known during its rule for ferocity against those seen as violating its strict interpretation of Islam, the oppression of women and attacks against minority Shi'ite Muslims.
Additional reporting by Mark Hosenball and Andrew Quinn; Editing by Peter Cooney