"If al-Zawahiri was doing so against Bin Ladin's directives, then Bin Ladin did not have a firm grip on al-Qa`ida itself, let alone its so-called affiliates," they wrote. "Al-Zawahiri might have assumed that Bin Ladin would not publicly refute him," they added.
The released letters do not however provide concrete evidence of a power grab by Zawahiri. If anything they suggest that force of circumstance had led to Atiyah supplanting both the Saudi and the Egyptian in operational matters. The released letters indicate Atiyah still valued bin Laden's input, made a show of deference to him, and gave him detailed briefings, even if his tone sometimes suggested exasperation with bin Laden's insatiable need to be updated on operational issues. There was no suggestion in the documents that bin Laden felt his directives were not being followed.
The documents show Atiyah and Zawahiri were in touch, but do not reveal how frequent were the communications between them, nor the degree to which the Egyptian was able to push his strategic vision. Zawahiri only confirmed Atiyah's death around three months after he was killed in a drone strike, suggesting it may have taken time to exchange news between their two locations.
Bin Laden's letters suggest that by the end of the 2000s he and Zawahiri had for at least a period of time different positions on violent Jihad in the Arab Muslim world.
Bin Laden in a May 2010 letter to Atiyah argued that outside Iraq, Afghanistan, and Somalia, it was premature to wage such campaigns, and resources should instead by be focused on attacking the United States. "The only way to remove this hegemony is to continue our direct attrition against the American enemy until it is broken and too weak to interfere in the matters of the Islamic world," bin Laden wrote.
Bin Laden's reluctance for Jihadist fronts to be opened in the Arab Muslim world was in part a product of his concern over the backlash created by the rising number of Muslims killed by al Qaeda terrorism. "After the war expanded and the Mujahidin spread out into many regions, some of the brothers became totally absorbed in fighting our local enemies, and more mistakes have been made due to miscalculations by the brothers in planning the operations," he wrote.
Zawahiri, by contrast, in tapes he released in 2009 gave rhetorical support for violent opposition to regimes by affiliated Jihadist groups in the Islamic Maghreb and Yemen. For many years one of his key strategic maxims had been for Jihadists to seize territory in the Arab Muslim world, as a base for future expansion in the region.
"Make [the Mujahideen] a thorn in the throats of the Crusaders and their agents like the House of Saud and Ali Abdullah Saleh," Zawahiri stated in a February 2009 audiotape.
Bin Laden, having been burned by his failed attempts to topple the Saleh regime in the early 1990s, in his 2010 letter to Atiyah argued for "halting the escalation in Yemen" at a time when AQAP was beginning to intensify its attacks on Yemeni security forces.
"We should not begin to attempt to establish a government in Yemen, even if the people revolted against the government and toppled it, either in south Yemen or in all of Yemen," bin Laden wrote.
"If the Yemenis were to begin a long battle against the security services, this is a matter that will weigh on the people," bin Laden wrote. He added that Jihadists could "not provide for the people's needs in light of the battle and siege of the whole world against us."
For some reason he then softened his opposition. By the summer of 2010 bin Laden was at least willing to entertain the idea of backing AQAP's campaign of violence. In an August letter he asked Atiyah to get more information from AQAP leader Nasir al Wuhayshi about the "battlefield in Yemen so it is feasible for us, with the help of God, to make the most appropriate decision to either escalate or calm down."
Bin Laden and Zawahiri's debates on whether to allocate priority to attacking the "near" or "far" enemy had a long pedigree. In the late 1980s and early 1990s Zawahiri won over an initially reluctant bin Laden to the need for regime change in the Arab world, while in the mid to late 1990s bin Laden persuaded Zawahiri that only by attacking the United States, and removing its influence from the region, could they hope to create a new theocratic order there. Throughout Zawahiri was relatively more focused than the Saudi on the need to topple regimes in the Arab world, particularly in Egypt.
In a taped address in March 2011, Zawahiri stepped up his support for AQAP's campaign of violence. "I encourage them to uproot this regime ... you have begun your uprising, so continue it until Yemen is liberated from the Crusaders and their agents," he said. A draft of the speech with suggested tweaks in green highlight from an unknown editor was found in Abbottabad.
Bin Laden may have been coming round to this argument in the last weeks of his life - writing in April 2011: "Initially I would see one of the most important steps of the oncoming stage is inciting the people who have not revolted yet, and encouraging them to get against the rulers ... so the arrows are concentrated on toppling the rulers."
A Shared Response to the Arab Spring
The April 2011 letter was written six days before bin Laden was killed by Navy Seals, and also included a taped statement on the unprecedented events in the Arab world, which was broadcast only after his death in which he congratulated the protestors in Tunisia and Tahrir Square in Egypt (very few of whom had any sympathy for al Qaeda) and rhetorically appropriated their victory as his own.
"I want to talk about the most important point in our modern history," he wrote to Atiyah, "things are strongly heading towards the exit of Muslims from being under the control of America."
Bin Laden called on followers to guide and advise the revolutionary movements, and spread the "correct understanding." He also instructed al Qaeda's senior ideologues to concentrate all their firepower on events in the Arab world.
"There is no doubt that the duties on the mujahideen are numerous, except that this great duty should take the main share of our efforts," Bin Laden wrote. After their differences in previous years, bin Laden and Zawahiri were once again united on the need to refocus the group's resources on the Arab world.
In the end it was the Egyptian, not bin Laden, who shaped al Qaeda's response to the Arab Spring and its current stance towards potential affiliates.
Bin Laden's last letter revealed that many al Qaeda operatives were clamoring to return to the Arab world from the Afghanistan-Pakistan region. He instructed Atiyah that those that were sent back should be sent only by safe routes.
Around the time of bin Laden's death, Zawahiri dispatched lieutenants to build up al Qaeda's presence in Libya, according to a source briefed by Western intelligence. He was apparently aiming to rebuild al Qaeda's presence in the Arab world, create a new network of clandestine cells in the region, and restore its popularity by casting itself as the defender of Sunni Muslims in ongoing conflicts between insurgent forces and regimes in Syria and Yemen.
"The current situation has brought unprecedented opportunities," bin Laden wrote in his last letter.