The U.S. dealt a significant blow to al Qaeda leader Ayman al-Zawahiri when an American drone aircraft killed his right-hand man, say terrorism experts, but they caution the group has a deep bench to fill the void.
U.S. officials confirmed Tuesday that a drone strike in Pakistan killed Abu Yahya al-Libi, the group's most significant setback since Osama bin Laden was killed in May 2011.
"There's no doubt this is significant. He had a unique set of skills that made him an up-and-comer," says Rick "Ozzie" Nelson of the Center for Strategic and International Studies. "He was charismatic, like bin Laden was. He was more of a scholar. ... And he was a seasoned operator. Someone with those three characteristics will be very hard to replace."
Read more about the al Qaeda leader killed Monday.