Escalated airstrikes and special operations raids have disrupted Taliban movements and damaged local cells. But officials said that insurgents have been adept at absorbing the blows and that they appear confident that they can outlast an American troop buildup set to subside beginning next July.

“The insurgency seems to be maintaining its resilience,” said a senior Defense Department official involved in assessments of the war. Taliban elements have consistently shown an ability to “reestablish and rejuvenate,” often within days of routed by U.S. forces, the official said, adding that if there is a sign that momentum has shifted, “I don’t see it.”…

The blunt intelligence assessments are consistent across the main spy agencies responsible for analyzing the conflict, including the CIA and the Defense Intelligence Agency, and come at a critical juncture. Officials spoke on the condition of anonymity because they are not authorized to discuss the matter publicly…

U.S. officials said Taliban operatives have adopted a refrain that reflects their focus on President Obama’s intent to start withdrawing troops in the middle of next year. Attributing the words to Taliban leader Mohammad Omar, officials said, operatives tell one another, “The end is near.”