A sharply escalated campaign of CIA drone strikes in Pakistan is aimed in part at al-Qaeda units suspected of planning terrorist attacks on targets in Europe, a threat that U.S. officials described as "credible but not specific" enough to allow authorities to anticipate precisely where or when a strike might occur.
The intensified bombing of targets in North and South Waziristan represents an expansion of the secret drone program from its origins as a weapon used in a selective hunt for high-ranking operatives to one now delivering a barrage of strikes in the hopes of disrupting a still-murky plot.