Following the death of bin Laden, former U.S. Deputy National Security Advisor for Combating Terrorism Juan Zarate said that al-Zawahiri would "clearly assume the mantle of leadership" of al-Qaeda. However, a senior U.S. administration official said that although al-Zawahiri was likely to be al-Qaeda's next leader, his authority was not "universally accepted" among al-Qaeda's followers, particularly in the Gulf region. Zarate said that al-Zawahiri was more controversial and less charismatic than bin Laden. Rashad Mohammad Ismail (AKA "Abu Al-Fida"), a leading member of al-Qaeda in the Arabian Peninsula, stated that al-Zawahiri was the best candidate.