U.S. intelligence officials, however, were more cautious in their interpretation of the evidence. Although U.S. analysts acknowledged historical ties between Lashkar and ISI, as well as more recent contacts between militants and Pakistani intelligence officers, they said they were not convinced that Pakistan supported the attacks in any significant way.

“Even if there were contacts between ISI and Lashkar-i-Taiba, it’s not the same as saying there was ISI support,” said a U.S. counterterrorism official, speaking on the condition of anonymity. The official would not dismiss the possibility that further evidence would reveal active ISI involvement but said: “The evidence we’ve seen so far does not get you there.”