KABUL, Afghanistan — For the second time in less than a year, senior Taliban leaders have convened in the Pakistani city of Quetta to deliberate how to replace a dead supreme leader.

Unlike last summer’s gatherings, where some leaders arrived in convoys of hundreds of vehicles to choose Mullah Akhtar Muhammad Mansour as the successor to their founding leader, Mullah Muhammad Omar, Taliban figures described the tone of the meetings over the past three days as decidedly low-key, and even shocked.

They described how the American drone strike that was said to have killed Mullah Mansour in Pakistan’s Baluchistan Province on Saturday also destroyed the perception that the protection they had received for years in their Pakistani havens could be permanent. Some angrily accused Pakistani intelligence agents of selling out Mullah Mansour’s location to the Americans.

Taliban spokesmen and commanders were happy to jump on the phone last summer, first to reject news of Mullah Omar’s death and then to project an image of unity behind Mullah Mansour. This time, there has been mostly silence. Several commanders and participants who could still be reached said the days of heedless cellphone communication in Baluchistan were gone — another casualty of the American drone strike that some officials said was aided by Mullah Mansour’s repeated use of a small collection of phones.