In recent years Al Qaeda Central has also seeded a number of franchises around the Middle East and North Africa that are now acting in a Qaeda-like manner, despite having little or no contact with bin Laden. In September 2009 the Somali Islamist insurgent group Al-Shabab (“the youth”) pledged its allegiance to Al Qaeda’s leader. Today Al-Shabab controls a swath of central Somalia. Worryingly, the group has also shown that it is capable of carrying out operations outside Somalia, bombing two groups of fans watching the World Cup in Uganda on July 11, 2010, attacks that killed more than 70.

Al Qaeda in the Arabian Peninsula (AQAP) has shown an even longer reach. It was the group responsible for Abdulmutallab’s botched attempt to explode a bomb hidden in his underwear on Northwest Flight 253 over Detroit. Several counterterrorism officials tell me they believe that the Yemeni-based builder of Abdulmutal-lab’s bomb is still at large, and that the bomb maker is likely to try again to bring down a commercial jet with a concealed bomb invisible to metal detectors.

This level of threat is likely to persist for years to come. Al Qaeda may no longer be able to launch an attack sufficiently deadly to completely reorient U.S. foreign policy, as the 9/11 attacks did. But there has been a key shift since around the time President Obama took office: the Americanization of the leadership of Al Qaeda and aligned groups. Anwar al-Awlaki, a Yemeni-American cleric who grew up in New Mexico, is today playing an important operational role in AQAP and had some part in recruiting the underwear bomber, according to counterterrorism officials. Adnan Shukrijumah, a Saudi-American who grew up in Brooklyn and Florida, is now Al Qaeda’s director of external operations. In 2009 he allegedly tasked Najibullah Zazi and two other Americans to attack targets in the United States. Omar Hammami, an Islamic convert from Alabama, is both a key propagandist and a military commander for Al-Shabab, while Chicagoan David Headley played a central role in scoping the targets for the 2008 attacks in Mumbai that killed more than 160.

Al Qaeda and like-minded groups have attracted dozens of U.S. citizens and residents as foot soldiers. According to a count by Andrew Lebovich of the New America Foundation, in 2009 at least 43 American citizens or residents aligned with Sunni militant groups or their ideology were charged with terrorism crimes in the United States or elsewhere, the highest number in any year since 9/11. So far in 2010, at least 18 have been similarly charged or convicted.

Bin Laden remains important as the guiding icon that is drawing these people to jihad. Yet U.S. intelligence agencies have not had any “actionable intelligence” about his location since he disappeared in mid-December 2001 after the battle of Tora Bora. Informed hypotheses put him in or around Pakistan’s tribal regions, but these are only educated guesses (albeit rather expensive ones, given that U.S. intelligence agencies have sucked up some half a trillion dollars since the 9/11 attacks).

While bin Laden himself may have vanished like a wraith, intelligence about other militant leaders in the Pakistani tribal areas has markedly improved in the past couple of years. In 2007 there were just three drone strikes reported there; in 2008 there were 34; the Obama administration has already authorized more than 100. Those drones have killed at least a dozen mid and upper-level leaders of Al Qaeda or the Taliban. One apparent result is how few propaganda tapes Al Qaeda’s leaders are issuing. The number of tapes released in 2010 by Al Qaeda’s No. 2, Ayman al-Zawahiri, has been his smallest in seven years. Bin Laden has also fallen relatively silent, seemingly more worried about staying alive than staying relevant. Still, as he enters late middle age—family members say he turned 53 in February—he may take some satisfaction that his message continues to resonate with all too many disaffected men, from Connecticut to Kandahar.