Editor's note: Peter Bergen, CNN's national security analyst, is a fellow at the New America Foundation, a Washington-based think tank that promotes innovative thought from across the ideological spectrum, and at New York University's Center on Law and Security. He's the author of "The Osama bin Laden I Know: An Oral History of al Qaeda's Leader."



Peter Bergen says Osama bin Laden is still alive and still significant eight years after September 11.



HELMAND, Afghanistan (CNN) -- Eight years after September 11, the "war on terror" has gone the way of the dodo. And President Obama talks instead about a war against al Qaeda and its allies.



What, then, of al Qaeda's enigmatic leader, Osama bin Laden, who has vanished like a wisp of smoke? And does he even matter now?



The U.S. government hadn't had a solid lead on al Qaeda's leader since the battle of Tora Bora in winter 2001. Although there are informed hypotheses that today he is in Pakistan's North West Frontier Province on the Afghan border, perhaps in one of the more northerly areas such as Bajaur, these are essentially guesses, not "actionable" intelligence.



A longtime American counterterrorism analyst explained to me, "There is very limited collection on him personally."



That's intelligence community shorthand for the fact that the usual avenues of "collection" on a target such as bin Laden are yielding little or no information about him. Those avenues typically include signal intercepts of phone calls and e-mails, as well as human intelligence from spies.



Given the hundreds of billions of dollars that the "war on terror" has consumed, the failure to capture or kill al Qaeda's leader is one of its signal failures.



Does it even matter whether bin Laden is found? Yes, it does. First, there is the matter of justice for the almost 3,000 people who died in the September 11 attacks and for the thousands of other victims of al Qaeda's attacks around the world.



Second, every day that bin Laden remains at liberty is a propaganda victory for al Qaeda.



Third, although bin Laden and his deputy Ayman al-Zawahiri aren't managing al Qaeda's operations on a daily basis they guide the overall direction of the jihadist movement around the world, even while they are in hiding.



Those messages from al Qaeda's leaders have reached untold millions worldwide via television, the Internet and newspapers. The tapes have not only instructed al Qaeda's followers to continue to kill Westerners and Jews, but some also carried specific instructions that militant cells then acted on.



In March 2008, for instance, the al Qaeda leader denounced the publication of cartoons of the Prophet Mohammed in a Danish newspaper as a "catastrophe" for which punishment would soon be meted out. Three months later, an al Qaeda suicide attacker bombed the Danish Embassy in Islamabad, killing six.



Some reading this may think: But what's the proof that the al Qaeda leader is still alive? Plenty. Since September 11, bin Laden has released a slew of video and audiotapes, many of which discuss current events. After a nine-month silence, for instance, bin Laden released a 22-minute audiotape on March 14, sharply condemning the recent Israeli invasion of Gaza.



Are these tapes real? Not one of the dozens of tapes released by bin Laden after 9/11 has been a fake. Indeed the U.S. government has authenticated many of them using bin Laden's distinctive voiceprint.



And what about the persistent reports that he is ill? In 2002, Pakistani President Pervez Musharraf said bin Laden had kidney disease, for which he required a dialysis machine, and was therefore likely dead. But the stories of bin Laden's life-threatening kidney problems are false, judging by his appearance in videos that he released in 2004 and again in 2007, in which he showed no signs of illness.



On the 2007 tape, the al Qaeda leader had even dyed his white-flecked beard black, suggesting that as the Saudi militant entered his fifth decade, he was not
The war on terror has failed to capture who? Who still inspires al Qaeda? Who has yet to be captured?
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