Recent targeted attacks that killed militants in Somalia, Indonesia and Pakistan have chipped away at al-Qaida's power base, sapping the terror network of key leaders and experienced operatives who train recruits and wage attacks.
Intelligence officials said Friday that the military strikes have reduced al-Qaida's core leadership to only a handful of men and diminished its ability to train fighters. This, they said, has forced al-Qaida to turn to its global affiliates for survival.
The killings of Saleh Ali Saleh Nabhan in Somalia, Noordin Muhammed Top in Indonesia and Baitullah Mehsud in Pakistan — all in recent weeks — have been the latest blow.
A U.S. counterterrorism official, speaking on condition of anonymity because he was not authorized to speak on the subject, said the deaths deal "a major near-term blow to their respective militant groups."
Since the start of the year, American forces have stepped up strikes against militants in terrorist hubs, including Pakistan and Somalia. U.S. National Intelligence Director Dennis Blair said this week that such strikes have been possible because of a greater understanding of al-Qaida.
British intelligence agents have joined the United States in stepping up counterterrorism measures and adding agents, leading to fewer fully developed terrorist plots being uncovered in Britain.
Still, al-Qaida's top leaders — Osama bin Laden and his No. 2, Ayman al-Zawahri — remain free, and terrorist bombings continue to roil countries from Asia to Africa as al-Qaida and the Taliban establish links with satellite groups.
Curbing al-Qaida's expansion
This week, suicide bombers in Somalia killed 21 people, including 17 peacekeepers, in twin attacks at an African Union base in Mogadishu.
The attacks were said to be in retaliation for the U.S. commando raid Monday in southern Somalia that killed Nabhan — the leader of the powerful Islamist group Al-Shabab, which was using foreign fighters to help al-Qaida expand deeper into the Horn of Africa.
Nabhan was one of the founders of al-Shabab, a group that didn't exist a decade ago.
Nabhan — a Kenyan with Yemeni roots who had years of strategic and weapons training — was being used to build alliances. He was also key in procuring weapons and funds, and training recruits, according to Rohan Gunaratna, author of "Inside Al Qaeda: Global Network of Terror."
His death, along with the killing of reputed Shabaab commander Aden Hashi Ayro in Somalia last year, highlights al-Qaida's challenge in expanding in Africa.
Mehsud's death in Pakistan last month represented a similar blow. Mehsud was the leader of the Taliban in Pakistan.
Strikes against militant leaders in Pakistan have been particularly important for Britain. About 75 percent of the terrorist plots against the U.K. have roots in Pakistan.
A plot to down at least seven trans-Atlantic airliners in 2006 was thwarted partially because counterterrorism officials intercepted coded e-mails between a British terror cell and their handlers in Pakistan, prosecutors said during a trial where three men were convicted in the plot.
Mehsud, who underwent extensive training in Afghanistan before 9/11, acted as a unifying force among Taliban factions.
In addition to his death, Ilyas Kashmiri — an al-Qaida operations chief in northwest Pakistan — was also believed to have been killed in North Waziristan by missiles fired by U.S. drones. Kashmiri was accused of playing a role in the failed assassination attempts against former Pakistan President Pervez Musharraf.
A Pakistani intelligence official, who spoke on condition of anonymity because of the sensitivity of his work, said it appeared many factions were starting to fight among themselves for leadership, and ranks are turning on each other because they are suspicious and the finances are slowing.
Al-Qaida's capacity to communicate, instigate, organize, commission and execute spectacular terrorist attacks has been severely diminished in the past two years, particularly because of successful drone attacks in Pakistan, according to Jason Burke, author of "Al-Qaida: The True Story of Radical Islam."
Before the Sept. 11 terror attacks in 2001, al-Qaida provided fighters with extensive four-month training sessions at camps in Afghanistan. Now, training has been driven underground and recruits lack real battle experience, counterterrorism experts said.
A lack of an experienced pool of leaders has sparked bitter infighting among members vying for power.
In Indonesia, there is no clear successor for Noordin Muhammed Top, who was killed this week during a gunfight with police seeking suspects in the July bombings of two Jakarta hotels.
Top was identified by authorities as the leader of al-Qaida in Southeast Asia. He had also been implicated in every major attack in Indonesia since 2002, including two bombings on the resort island of Bali that together killed 222 people, mostly foreigners.