The revolutions that swept the Middle East and North Africa also emptied prisons of militants, a problem now emerging as a potential new terrorist threat. Fighters linked to one freed militant, Muhammad Jamal Abu Ahmad, took part in the Sept. 11 attack on U.S. diplomatic outposts in Libya that killed four Americans, U.S. officials believe based on initial reports. Intelligence reports suggest that some of the attackers trained at camps he established in the Libyan Desert, a former U.S. official said. Western officials say Mr. Ahmad has petitioned the chief of Al Qaeda, to whom he has long ties, for...
