In the early months of 1996, agents working in the windowless white cubbyholes of the CIA's Counterterrorist Center made a strategic decision. A joint CIA-FBI investigation into the misdeeds of World Trade Center bomber Ramzi Ahmed Yousef had uncovered a treasure of unexpected data about someone the agents concluded was even more dangerous. His name was Osama bin Laden.

The international effort bore fruit Thursday, with the arraignment in New York of Mohammed Rashed Daoud Owhali on 14 charges of murder, conspiracy to commit murder and use of weapons of mass destruction in connection with the Aug. 7 bombing of the U.S. Embassy in Nairobi, Kenya.

Behind Owhali, U.S. officials believe, lurks the shadowy hand of Bin Laden and a clandestine network of terrorist cells that calls itself Al Qaida ("The Base") and operates across a swath of territory stretching from Algeria to the Philippines.