Al-Qaeda announced Thursday Ayman al-Zawahiri will succeed assassinated terror mastermind Osama Bin Laden as its new leader, the Washington Post reports.

Egyptian bon Al-Zawahiri, Al Qaeda's operational commander and second-in-command, had increasingly been the international terror organization's public face in recent years and, following Bin Laden's death, was widely considered his most likely successor.

Al-Zawahiri, 59, a surgeon who spent years in underground Islamic groups in Egypt before joining Al-Qaeda, is a deeply religious Muslim who had the skill and experience to help turn an Afghan guerrilla movement into the global terrorist organization Al-Qaeda is today.

However, Al-Zawahiri is also considered rigid and lacking in charisma, and terrorism experts say it is unclear whether he can rebuild an organization that has been diminished by a prolonged siege by US military and intelligence forces.

US officials and terrorism analysts previously speculated Al-Zawahiri would face competition for Bin Laden's throne from other candidates, such as Libyan jihadis Atiyah Abd al-Rahman and Abu Yahya al-Libi, both of whom were considered more personable, or Ilyas Kashmiri, the head of Harkat-ul-Jihad-al-Islami, who was killed in a US targeted killing earlier this month.

But Al-Zawahiri finds himself assuming command of an Al-Qaeda whose central leadership has been weakened by repeated US airstrikes, with its Yemen branch, instead of its traditional Afghan core, being the organization's most dynamic and successful arm.

Two of Al-Qaeda’s senior operatives were killed in the past few weeks: the previously mentioned Kashmiri, who was implicated in the 2008 Mumbai attacks, and Fazul Abdullah Mohammed, believed to have planned the 1998 US Embassy bombings in East Africa.

US. forces have launched dozens of strikes this year on suspected Al-Qaeda hideouts near Pakistan’s border with Afghanistan.

Al-Zawahiri emerged as Al-Qaeda’s most visible spokesman in the years since the Sept. 11, 2001, attacks but his years of service and "Al-Qaeda-Brand" face may not prove sufficient cohesion for a group in need of a charismatic battle leader as it regroups under pressure from the world's foremost military power.

Only time will tell.