Inside the National Security Agency’s massive headquarters at Fort Meade, Maryland—a complex so large that the U.S. Capitol Building could easily fit inside it several times over—analysts wearing earphones sit twisting dials and scanning frequencies, hoping to lock on to one of their assigned targets. On November 3, 2002, in Room 3E132, personnel assigned to the agency’s Special Support Activity, which provides sensitive assistance to military commanders around the world, were in constant touch with a Cryptologic Support Group team in Yemen. The CSG—an NSA in microcosm, designed to be sent to critical areas on short notice—was part of a U.S. National Intelligence Support Team working with Yemeni intelligence officials to try to track down al-Qaeda members. Completing the team were Yemen-based CIA officials and their battery of unmanned Predator drones, each armed with deadly Hellfire missiles, based across the Red Sea in Djibouti. From there, the drones could easily reach anywhere in Yemen.
The CSG team was also patrolling the ether, hunting for any signals linked to its targets. High among those targets was Qaed Salim Sinan al-Harethi, a native Yemeni suspected of belonging to al-Qaeda and planning the attack on the USS Cole two years before. But like most of the NSA’s new targets, Harethi knew that the United States was searching for him with an electronic dragnet, hoping to snag a brief satellite phone call and determine his location. He carried with him up to five phones—each one, analysts suspect, equipped with multiple cards to change its number. The NSA had a partial list of his numbers and, because Harethi was such a high-priority target, had set up an alarm to go off if any of them was used.