WASHINGTON — A strike by an unmanned drone last week killed a senior commander of Al Qaeda who had played a significant role in planning the killing of Central Intelligence Agency operatives in late December at a base in Afghanistan, according to American officials.  The March 8 strike was one of a series aimed at suspected participants in the deadly attack in Khost Province, which took place just before a meeting with a militant who the Americans believed could provide information on Al Qaeda’s operations. Seven Americans and a Jordanian intelligence officer died in that attack.  According to a United States counterterrorism official, the Qaeda operative killed last week was Hussein al-Yemeni. The drone missile struck in Miram Shah in North Waziristan, a part of Pakistan where Al Qaeda is considered well dug in.  The official, who spoke on the condition of anonymity, described Mr. Yemeni as an “Al Qaeda planner and facilitator” in his late 20s or early 30s, who had established ties with the Haqqani network, which has planned many Taliban attacks in Afghanistan, and with Al Qaeda in the Arabian Peninsula. His role was described by one American official as a “conduit in Pakistan for funds, messages and recruits, but his real specialty was bombs and suicide operations.”  It was unclear exactly what role Mr. Yemeni might have played in preparing the Jordanian double-agent, Humam Khalil Abu Mulal al-Balawi, also known as Humam Khalil Mohammed, for his meeting in Khost on Dec. 30. Mr. Balawi was not searched when entering the compound, and detonated his suicide vest just before he was to be patted down ahead of his meeting with a number of C.I.A. officials. In an unusual statement, a senior intelligence official told reporters the deaths would be “avenged through successful, aggressive counterterrorism operations.”  The drone attacks are part of a covert program that American officials officially refuse to talk about, but whose existence is an open secret. Last year there were roughly 55 drone attacks in Pakistan against Al Qaeda and the Taliban, based on news reporting about the damage they caused. The attacks are a key element of an effort to put pressure on Al Qaeda and its leadership, but in recent weeks they appear to have been used to kill those believed responsible for the Khost attack.  In a speech last week in Oklahoma, the C.I.A. director, Leon Panetta, said he believed that the pressure on Al Qaeda had grown so much in recent months that the leadership of its traditional hierarchy, including Osama bin Laden, had been greatly diminished. He said recent communications intercepts had overheard younger militants complaining about the absence of leadership.  At the end of the Bush administration, intelligence officials made similar claims. At the same time, some officials concede, an operation as complex as that in Khost demonstrates that Al Qaeda and the Taliban can still carry out sophisticated terror actions.
A recent drone strike killed a commander who helped plan the killing of C.I.A. staff at an Afghanistan base.