The central justification of the U.S.-NATO war against the Afghan Taliban – that the Taliban would allow al Qaeda to return to Afghanistan – has been challenged by new historical evidence of offers by the Taliban leadership to reconcile with the Hamid Karzai government after the fall of the Taliban government in late 2001.
The evidence of the Taliban peace initiatives comes from a new paper drawn from the first book-length study of Taliban- al Qaeda relations thus far, as well as an account in another recent study on the Taliban in Kandahar province by journalist Anand Gopal.
In a paper published Monday by the Center on International Cooperation at New York University, Alex Strick van Linschoten and Felix Kuehn recount the decision by the Taliban leadership in 2002 to offer political reconciliation with the U.S.-backed Afghan administration.
Citing an unidentified former Taliban official who participated in the decision, they report that the entire senior Taliban political leadership met in Pakistan in November 2002 to consider an offer of reconciliation with the new Afghan 
government in which they would "join the political process" in Afghanistan.
"We discussed whether to join the political process in Afghanistan or not and we took a decision that, yes, we should go and join the process," the former Taliban leader told the co-authors.
They cite an interlocutor who was then in contact with the Taliban leadership as recalling that they would have returned to Afghanistan to participate in the political system if they had been given an assurance they would not be arrested.
But the Karzai government and the United States refused to offer such an assurance, the interlocutor recalled. They considered the Taliban a "spent force", he told Strick van Linschoten and Kuehn.
Gopal, who has covered Afghanistan for the Christian Science Monitor and the Wall Street Journal, provided a similar account of the Taliban attempt to reconcile with the Karzai government in a lengthy study published by the New America Foundation last November, based on his interviews with present and former Taliban as well as with officials in the office of President Karzai.
The entire senior Taliban leadership, meeting in Karachi, "agreed in principle to find a way for them to return to Afghanistan and abandon the fight", Gopal wrote, but the initiative was frustrated by the unwillingness of the United States and the Afghan government to provide any assurance that they would not arrested and detained.
The Taliban continued to pursue the possibility of reconciliation in subsequent years, with apparent interest on the part of the Karzai government, according to Gopal. Delegations "representing large sections of the Taliban leadership" traveled to Kabul in both 2003 and 2004 to meet with senior government officials, according to his account.
But the George W. Bush administration remained uninterested in offering assurances of security to the Taliban.
Robert Grenier, then the CIA station chief in Islamabad, revealed in an article in al Jazeera Jan. 31, 2010 that former Taliban foreign minister Wakil Ahmed Muttawakil had been serving as an intermediary with the Taliban on their possible return to Afghanistan in 2002 when he was "arrested and imprisoned for his pains".
The CIA sought to persuade the U.S. Defence Department to release Muttawakil, according to Grenier. But Muttawakil remained in detention at Bagram Airbase, where he was physically abused, until October 2003.
The new evidence undermines the Barack Obama administration’s claim that Taliban-ruled areas of Afghanistan would become a "sanctuary" for al Qaeda.
Strick van Linschoten and Kuehn suggest that the proposed reintegration of the Taliban into a political system that had been set up by the United States and its allies was "totally alien to al-Qaeda ideology but logical for the Taliban".
They acknowledge that the Taliban have welcomed the support and assistance of al Qaeda cadres in the war. But they argue in the new paper that the relationship is a "marriage of convenience" imposed by the foreign military presence, not an expression of an ideological alliance.
They also cite evidence that the Taliban leadership recognise that they will have to provide guarantees that a Taliban-influenced regime in Afghanistan would not allow al Qaeda to have a sanctuary.
They note in particular a Taliban public statement released before the London Conference of January 2010 that pledged, "We will not allow our soil to be used against any other country."
An earlier Taliban statement, distributed to news media Dec. 4, 2009, said the "Islamic Emirate of Afghanistan" – the term used by the insurgent leadership to refer to the organisation – had "no agenda of meddling in the internal affairs of other countries and is ready to give legal guarantees if foreign forces withdraw from Afghanistan".
Independent specialists on the history of the relationship have long questioned that assumption, and have emphasised that the Taliban leadership was never very close to al Qaeda.
Leah Farrell, senior counter-terrorism intelligence analyst with the Australian Federal Police from 2002 to 2008, wrote in her blog that the relationship "is not a marriage, it’s friends with benefits". Farrell has also said that jihadi accounts of the late 1990s have shown bin Laden was not that close to Taliban spiritual leader Mullah Mohammed Omar before the 9/11 attacks.
The new paper, based on both Taliban and jihadist documents and from interviews with Taliban and former Taliban officials, points to basic differences of ideology and interest between the Taliban and al Qaeda throughout the history of their relations.
Relations between Taliban and al Qaeda leaders during the second half of the 1990s were "complicated and often tense", according to Strick von Linschoten and Kuehn, even though they were both Sunni Muslims and shared a common enemy.
They recall that al Qaeda leader Osama bin Laden’s plotting against the United States was done in direct violation of Mullah Omar’s directives to him.
An e-mail from two leading Arab jihadists in Afghanistan to bin Laden in July 1999, which Wall Street Journal reporter Alan Cullison later found in a laptop that had once belonged to al Qaeda, referred to a "crisis" in relations between bin Laden and Mullah Omar that threatened the future of al Qaeda-sponsored training camps in Afghanistan. The message expressed fear that the Taliban regime might "kick them out" of Afghanistan.
Mullah Omar nevertheless regarded bin Laden as an "important connector" to the Muslim world, according to Strick van Linschoten and Kuehn. And the Taliban leadership faction that was pushing hard to force bin Laden out of the country was weakened by the death of its leading figure, Mullah Mohammed Rabbani, in April 2001.
Contrary to the suggestion that the Taliban were complicit with the Sep. 11, 2001 attacks, however, Strick van Linschoten and Kuehn assert that Mullah Omar and other leaders refused to hand over bin Laden to the United States mainly because of the fear of losing the few allies they had in the Muslim world.
They suggest that a primary reason for the Taliban decision not to give into U.S. pressure on bin Laden both before and after 9/11 was to maintain the support of Pakistan, which was encouraging them to hold out against those pressures.
Other published sources have confirmed that, even in October 2001, Pakistani intelligence officials were advising the Taliban to avoid handing over bin Laden, in the hope that the Taliban-al Qaeda resistance to the U.S.-led military offensive would continue.
Gareth Porter is an investigative historian and journalist with Inter-Press Service specialising in U.S. national security policy. The paperback edition of his latest book, "Perils of Dominance: Imbalance of Power and the Road to War in Vietnam", was published in 2006.