Prior to his death in May 2011, former al-Qaeda leader Osama bin Laden advised other organisation leaders to abandon their hideouts in Pakistan's tribal areas and move elsewhere because their hideouts were no longer effective as safe havens.

Bin Laden's advice proved to be prescient as another senior al-Qaeda figure, Abu Yahya al-Libi -- believed to have been second in command in al-Qaeda behind Ayman al-Zawahiri -- was killed in the area on Monday (June 4th).

Bin Laden's advice, contained in a message that was seized from his home in Abbottabad, Pakistan was based on his awareness that al-Qaeda was suffering heavy losses as a result of years of clashes with Pakistani security services and continued attacks by pilotless drones that killed dozens of al-Qaeda's veteran leaders.

Ayman al-Zawahiri, bin Laden's successor, was surely aware of bin Laden's analysis of the situation. He is now suffering its consequences first hand as he watches other leaders being killed at a rapid pace. The depletion in al-Qaeda's ranks is preventing al-Zawahiri from appointing replacements and does not allow him adequate time to assess who could take their place. The pace of losses during al-Zawahiri's tenure is perhaps even more intense than it was during bin Laden's.

Al-Libi played a role few could play

Al-Libi's importance, and the significance of his death for al-Qaeda, can be traced to his knowledge of sharia, which enabled him to serve as a religious scholar for the organisation. Few individuals in the organisation were qualified to hold such status. Al-Libi studied sharia under prominent scholars in Mauritania in the 1990s. Members of the Libyan Islamic Fighting Group sent him there to study religious jurisprudence, according to former leaders in the Libyan group.

Although al-Libi was not known to be a member of al-Qaeda before he fled to Pakistan in late 2001 when the Taliban was overthrown in Afghanistan, he emerged suddenly in 2005 as a prominent al-Qaeda leader. After he was arrested in Pakistan and transferred to Bagram airbase in 2002, al-Libi and three other prisoners escaped from prison in 2005. Soon afterward he joined al-Qaeda and began recording video and audio messages, gaining a reputation as an articulate speaker who used his knowledge of sharia to justify al-Qaeda's tactics and policies.

Al-Libi's public role included issuing religious pronouncements that attempted to justify al-Qaeda's position on crises in the Arab world, such as Somalia, Iraq, Palestine and the Maghreb.

He was one al-Qaeda's principal spokesmen during the Arab Spring demonstrations, which caught the organisation off guard. Al-Qaeda had emerged as a marginal organisation that had no role in the peaceful demonstrations that succeeded in overthrowing the regimes of Tunisia's Zine El Abidine Ben Ali and Egypt's Hosni Mubarak.

After bin Laden's death, it emerged that al-Libi had performed other functions in al-Qaeda's name that were not publicly known, including coercing al-Qaeda's affiliates to adhere to the organisation's policies.

One of his most notable acts was a severely worded reprimand he co-wrote with another Libyan al-Qaeda leader, Atiya Abdel Rahman, that was addressed to Hakimullah Mehsud, the leader of the Pakistani Taliban. The letter objected to the bombings and killings that Mehsud's group conducted, including the bombing of mosques and public markets.

Al-Libi is also believed to have served as a liaison between al-Qaeda's leadership in Waziristan and its affiliates in the Maghreb and Somalia.

Al-Zawahiri in a hard place

Al-Zawahiri will not easily replace al-Libi, who worked primarily as al-Qaeda's director general, directly below the al-Qaeda chief. His role was similar to one handled by another Libyan, Atiyah Abdel Rahman, who acted as the conduit for all messages to and from bin Laden until he was killed in August 2011.

His death could serve to convince al-Zawahiri that bin Laden was correct regarding the risk that al-Qaeda leaders were assuming if they stayed in Waziristan.

But even if al-Zawahiri is convinced of the assessment, it will not be easy for him to pull the rest of the organisation's leaders out of Waziristan because relocating from Pakistan would be considered an admission of defeat by al-Qaeda in an area that it was using as the seat of its authority.

If al-Zawahiri follows bin Laden's advice and moves al-Qaeda's leaders to Afghanistan from Pakistan, there is no guarantee the situation would be improved. He is probably aware of the fate of Saudi Sakhr al-Taifi, al-Qaeda's second in command in Afghanistan, who was killed in late May during a NATO air raid in Kunar province.

Ironically, bin Laden had advised his leaders to move to Kunar, arguing that its rugged terrain could provide them with the shelter they sought.