Osama bin Laden encouraged cooperation with all who wanted to topple late Libyan dictator Muammar Gaddafi, including with the Muslim Brotherhood and its leading ideologue Sheikh Yusuf Qaradawi, the al-Qaida leader's recently declassified diary shows. The Libyan uprising "opened the door to the jihadists," he wrote.

Bin Laden encouraged al-Qaida branches such as the Libyan Islamic Fighting Group (LIFG) to disregard doctrinal or sectarian differences with other Islamists.

In an undated email, bin Laden acknowledged communication between al-Qaida and Muslim Brotherhood elements. He noted that a Brotherhood member sent al-Qaida an email describing "factions who now adhere to true Islam, and there is also a powerful Salafist faction within the Brotherhood."

U.S. officials became aware of LIFG's al-Qaida links after they agreed to back the group's fight to topple Libyan dictator Muammar Gaddafi. LIFG's leaders "maintained ties to al Qa'ida during their struggle with the forces of former dictator Muammar al [Gaddafi]," Secretary of State Hillary Clinton's confidante Sidney Blumenthal told her in a July 2012 email.

An April 2011 Libyan intelligence document noted that elements of the Muslim Brotherhood and the LIFG cooperated in the early stage of the Libyan rebellion. Bin Laden's missive could explain why this close cooperation took place. The Muslim Brotherhood resorted to "[taqiyya]" or intentional deception, to hide their bid to create a caliphate while telling the press they wanted democracy, the Libyan intelligence document said.

Evidence shows that LIFG worked with a Qaradawi representative who belonged to Libya's Muslim Brotherhood to overthrow Gaddafi.

LIFG cooperated with the "international network of the [Muslim] Brotherhood," the Libyan document said without going into detail. Ali Al-Salabi – a man referred to by Clinton aide Jake Sullivan as "a key figure in the Libyan Muslim [B]rotherhood and Qaradawi's man in Libya" in a Feb. 28, 2011 email – allegedly helped the LIFG during the spring 2011 uprising. He also helped move money from the Qatari government to the militias, the UAE based Khaleej Times reported in July.

The Muslim Brotherhood lamented bin Laden's death in a U.S. Seal Team raid, calling it an "assassination" and implying that he engaged in "legitimate resistance" against the West.

Bin Laden's diary shows a surprising degree of pragmatism that may have presaged cooperation between al-Qaida and the Muslim Brotherhood in Libya.