BALTIMORE -- One day last year, a trusted courier for Osama bin Laden answered a phone call that might have been wholly unremarkable except for one thing -- the National Security Agency was apparently listening in.
That intercepted call helped American intelligence officials track the courier all the way to the walled compound in Pakistan where bin Laden was hiding. The discovery eventually led to last week's midnight assault by Navy SEALs who killed the al-Qaida leader, ending a pursuit that began in the mid-1990s.
A spokeswoman for the NSA said the agency would not offer more detail, and intelligence officials won't even confirm the account, which was reported by several news outlets quoting anonymous sources. And yet for the super-secret NSA, one of Maryland's largest employers with a work force of some 30,000 and a budget in the billions, this singular act of eavesdropping now stands as one of its most notable and conspicuous achievements.
While news coverage has largely focused on the raid itself and the Central Intelligence Agency interrogations that yielded the courier's identity, observers of the U.S. intelligence community say credit also belongs to two intelligence agencies: the NSA in Fort Meade, Md., which scours global communications for clues, and the National Geospatial-Intelligence Agency in Bethesda, Md., which provides mapping and other information.