The report, by a former senior CIA official, Rolf Mowatt-Larssen, who led the agency's hunt for weapons of mass destruction, portrays al-Qaeda's leaders as determined and patient, willing to wait for years to acquire the kind of weapons that could inflict widespread casualties. "If Osama bin Laden and his lieutenants had been interested in . . . small-scale attacks, there is little doubt they could have done so now," he wrote. Bush administration officials feared that bin Laden was close to obtaining nuclear weapons in 2003 after U.S. spies picked up a cryptic message by a Saudi affiliate of al-Qaeda referring to plans to obtain three stolen Russian nuclear devices. The intercepts prompted the U.S. and Saudi governments to go on alert and later led to an aggressive Saudi crackdown that resulted in the arrest or killing of dozens of suspected al-Qaeda associates.
After that, terrorists' chatter about a possible nuclear acquisition halted abruptly, but U.S. officials were never certain whether the plot was dismantled or simply pushed deeper underground.
"The crackdown was so successful," Mowatt-Larssen said, "that intelligence about the program basically dried up."
Link to the report is here.