Western intelligence officials estimate that there are less than 100 al-Qaeda-linked fighters in Afghanistan, and last year the United Nations split its sanctions list to separate the Taliban and al-Qaeda.
Both David Cameron and U.S. Secretary of State Hillary Clinton have said that some kind of political settlement involving the Taliban is key to the stability of Afghanistan once most western troops have withdrawn by 2014.
Some communications in the documents date back several years but others are said to be from only weeks before the raid on 2 May last year in which Osama bin Laden died.
"Questions and issues come up. They don't see eye to eye on everything but it's clear they understand they have an interest in co-operating [on attacks against NATO, Afghan government and Pakistani targets]," the source said. "Of those engaged in the conversation, two [Zawahiri and Omar] are still alive today and there is no reason to believe that either has substantially changed his views in the last year."
Zawahiri became leader of al-Qaeda following bin Laden's death.
The range of the al-Qaeda senior leadership's interlocutors revealed by the documents has also surprised investigators, the source said.
Bin Laden appears to have been in direct or indirect communication with Nigerian-based militant group Boko Haram, as well as many other militant outfits. As with the Taliban, the question of whether Boko Haram, which has been responsible for a series fo suicide attacks and bombings last year, is in touch with al-Qaeda or one of its affiliates has been hotly debated by analysts.
Documents in the cache show that leaders of the Nigerian group had been in contact with top levels of al-Qaeda in the past 18 months – confirming claims made to the Guardian newspaper in January by a senior Boko Haram figure.
Other papers in the haul are now likely to be declassified. They include memos apparently dictated by bin Laden urging followers to avoid indiscriminate attacks which kill Muslims and pondering a rebranding of al-Qaeda under a new name.
The documents include memos stating broad strategic aims but little "hands-on" planning, according to sources.
Despite the correspondence with Omar and other groups, Bin Laden still appears to have been largely out of touch with the day to day working of his organization. His communications were written on a computer in the compound in Abbottabad where he lived, loaded on to memory sticks and then sent from distant internet cafes by a courier. It was this courier who eventually led the CIA to the al-Qaeda chief.
A reliable account of Osama bin Laden's life on the run can now be established, pieced together from the testimony, viewed by the Guardian newspaper, of one of bin Laden's wives, the recollections of the ISI officers who interviewed her compiled by retired Pakistani Army Brigadier Shaukat Qadir, statements of militants detained by the U.S. published by WikiLeaks and interviews with former U.S. officials.
Following the collapse of the Taliban regime in November 2001, bin Laden's wives and children fled Afghanistan , traveling first to Karachi, the vast Pakistani port city, where they spent several months. bin Laden himself headed north into the remote Afghan province of Kunar after the battle of Tora Bora in December 2001. According to ISI officials quoted by Qadir, a senior militant detained by the ISI in 2006 told interrogators that bin Laden had met Gulbuddin Hekmatyar, the Afghan insurgent leader, in Kunar at this time. ISI officials also maintain that Khaled Sheikh Mohamed told them that the al-Qaeda chief was there.
Former American officials this weekend told the Guardian newspaper that there was considerable intelligence indicating that Bin Laden was in eastern Afghanistan and making occasional journeys across the border into Pakistan at this time.
By the summer of 2004, Bin Laden appears to have moved into Pakistan permanently. According to the testimony of his youngest, Yemeni-born wife, she and her two children were reunited with her husband in a house in a remote district of the rugged Swat valley, in northwest Pakistan, in March 2004, before moving to another safe house in a small town called Haripur, 20 miles from Abbottabad, that autumn. In early summer 2005 the family then moved into the newly constructed compound where they would spend the next six years. They were joined there by bin Laden's second wife and her three children.
According to ISI officers interviewed by Qadir, the location had been scouted a year previously by senior militant Abu Farraj al-Libbi who then traveled to Swat to get bin Laden's approval for the move. The al-Qaeda chief insisted that the land for the house be bought, not rented, and sketched out a design for the construction – currently in the possession of the ISI.
The al-Qaeda leader himself evaded detection while on the move by pretending to be an ailing Pashtun former militant, still on Pakistan's wanted list, who hoped to return home to die, Qadir has written.
Western security officials believe bin Laden's oldest wife joined him in Abbottabad after being released in deal between Iranian authorities and a Pakistani militant group holding an Iranian diplomat.
By November 2010, the crucial courier had been identified and located. He then led the hunters to the Abbottabad house.
Intellpuke: You can read this article by Guardian South Asia Jason Burke in context here: www.guardian.co.uk/world/2012/apr/29/bin-laden-al-qaida-taliban-contact