KABUL, Afghanistan - Six years after the Sept. 11, 2007, attacks, many presume that the man behind the murders of nearly 3,000 people is hiding in the tribal areas that straddle the Afghan-Pakistani border, not far from where he evaded U.S. forces and their Afghan allies in 2001.
Osama bin Laden reappeared Friday after nearly three years in a rambling half-hour video that U.S. intelligence officials said appeared to be authentic and to have been made recently.
That bin Laden apparently has been able to survive says a lot about the problems the United States faces in bringing him to justice.
Among the factors working in his favor, according to local officials and U.S. analysts, are conservative Muslim tribes with a tradition of protecting guests and a war-torn region of grueling terrain, seething anti-Americanism and poor intelligence-gathering.
At the same time, the Bush administration's campaign in Iraq has diverted troops, money and equipment from the hunt for bin Laden since late 2001, and Pakistani forces aren't able to operate effectively on their side of the border.
Bin Laden has used those advantages to secure safe harbor, probably in the tribal area of Pakistan bordering Afghanistan, rebuild al-Qaida's inner circle, train a new generation of jihadis and expand ties to Middle Eastern and North African terrorist groups, said U.S., Afghan and Pakistani officials and experts.
"It's just damned difficult," said a U.S. intelligence official, who requested anonymity because of the sensitivity of the issue, when he was asked why bin Laden hasn't been caught. "He's got good security and is very mindful of his personal safety. He does have a support network."
"He is a needle in a friendly haystack," said Jeffrey White, a former senior Defense Intelligence Agency analyst.
That's not to say that U.S. special forces and CIA teams haven't tried to run bin Laden and his chief ideologist and lieutenant, Ayman al Zawahri, to ground. A long list of senior al-Qaida and Taliban leaders have been taken out in airstrikes and special forces missions, but the top of the organizational chart has eluded them.
The United States can't take all the blame. Pakistan's inability to manage the unruly border region has turned it into a deathtrap for the Pakistani military and a semi-permanent sanctuary for Afghanistan's toppled Taliban government and the al-Qaida units who allied with it.
And Afghan forces - under-equipped, poorly trained and at times beholden to local warlords - haven't had much of an effect on their side of the border.
Beyond those thorny issues, the U.S. effort has been plagued by poor intelligence, turf battles and serious missteps.
It began in December 2001, when the Pentagon - ignoring a CIA request for U.S. troops - relied on a group of mercenary Afghan warlords to block bin Laden's escape from his stronghold of Tora Bora. One of the warlords opened his lines of defense, allowing bin Laden and hundreds of his followers to slip into Pakistan's tribal region.
In late 2005, a U.S. mission to nab Zawahri was canceled after a planned raid by a Navy SEAL unit ballooned into an operation involving hundreds of men.
An attempt to kill Zawahri with a missile strike in January 2006 reportedly killed four lower-level al Qaida operatives, as well as 10 women and children, stoking sympathy for bin Laden across Pakistan.
Hassan Abbas, a former midlevel Pakistani police officer who worked in the tribal region, said the war in Iraq had prevented the Bush administration from devoting sufficient resources, intelligence-gathering and energy to the manhunt.
"Going into Iraq was a distraction," said Abbas, who's a fellow at Harvard University's John F. Kennedy School of Government. "If a quarter of the money the U.S. is spending on Iraq had been spent on finding Osama bin Laden . . . it might be possible to get to his organization."
Bin Laden's ability to evade what may be history's largest manhunt owes itself in large measure to the lawless region along the Pakistani-Afghan border.
Tribal insurgents allied with the Taliban and al Qaida have created a virtually independent Islamic state in much of Pakistan's tribal belt and repulsed repeated U.S.-supported drives by the Pakistani army to bring the region under control.
"Once an armed force is defeated, what can we expect of them?" said Mirza Aslam Beg, former Pakistani army chief of staff, referring to Pakistani forces. "They are trying to save their own skin. What can they do for you (the United States)?"
Pakistani troops withdrew from the area under a truce with the insurgents last September, allowing hundreds of new Arab recruits to enter the region to train at new bases that bin Laden set up there, according to U.S. officials. The truce recently collapsed, and Pakistani troops have resumed their operations amid a barrage of suicide bombings and ambushes.
Pakistan's powerful military intelligence service, the Inter-Services Intelligence Directorate, was once the chief foreign patron of the Taliban. U.S. officials think that some ISI officers have continued backing the insurgents and have turned a blind eye to al Qaida - despite President Pervez Musharraf's denials - to maintain leverage over the Afghan government and ensure a continued flow of American aid to Pakistan.
"Although the Pakistanis have cooperated to an extent, I think it's been mixed," said John Brennan, a former veteran CIA counterterrorism officer who served as the first interim director of the National Counter-Terrorism Center. "I don't think that anyone would disagree that there are still (al Qaida) collaborators who are Pakistani military types."
At the same time, the Taliban have mounted a ferocious return in Afghanistan.
Taliban fighters have taken de facto control of one rural district after the next, moving from their southern heartland toward the Afghan capital. Allied drug lords have produced record crops of opium poppy, fueling corruption and violence. And civilian casualties from U.S. air strikes, anger over Iraq and U.S. support for Israel have dramatically boosted anti-Americanism and opposition to the Kabul government.
Given the insecurity, violence and anti-U.S. anger - even
among moderates - on both sides of the border, it's not surprising to many Afghans and Pakistanis that bin Laden is still on the loose.
Helaluddin Helal, a member of the Afghan parliament, said that while he served as deputy interior minister in 2002 and 2003, he became convinced that Pakistani intelligence officers were protecting bin Laden.
He said he'd pass intelligence reports to his Pakistani counterparts on the location of Taliban and al Qaida commanders in Pakistan, but to no avail.
"We would tell them we had information that al Qaida and Taliban leaders were living in specific areas. The Pakistanis would say no, you're wrong, but we will go and check. And then they would come back and say those leaders are not living there. They (Pakistani forces) were going to these places and moving the al Qaida or Taliban leaders."
Pakistani officials respond that bin Laden is more likely in Afghanistan, and al Qaida is as much a threat to their country as it is to the United States. If bin Laden has remained in Pakistan's border areas, it's because of the mountainous terrain and Pashtunwali, the tribal law that requires the protection of guests, they said.
"It's not possible for the government or the ISI in any way to support Osama or al-Zawahri, because they are attacking the government of Pakistan," said Talat Masood, a retired Pakistani brigadier general. "Do you mean to say that the same government that has lost more than 1,000 men is supporting these guys?"
Wahid Mujda, a former Taliban diplomat who lives in Kabul, said that even if the Pakistan government knew where bin Laden was, it would be difficult to arrest or kill him. He pointed out that a recent army crackdown on a relatively small mosque complex in Islamabad had led to weeks of heightened violence along the border, with dozens of soldiers killed and hundreds taken hostage.
"The Pakistanis don't want to sacrifice their national interests for the United States," he said. "There is no doubt that the arrest of bin Laden in Pakistan would create a lot of instability."
Several U.S. officials and experts said they thought the manhunt might be focusing on the wrong place, and some analysts said Friday that bin Laden might be wearing a fake beard in the videotape, suggesting that he might have shaved off the real one and escaped to a Muslim area of Southeast Asia where fewer Muslim men wear beards.
Others pointed out that top al-Qaida operatives in U.S. custody, including the chief planner of the Sept. 11 attacks, Khalid Sheikh Mohammed, were found in Pakistani cities, whose densely populated neighborhoods would make perfect hiding places for bin Laden.
"The cities may be more attractive," said another U.S. official, who requested anonymity because he wasn't authorized to speak publicly. "They are large. Predators (unmanned U.S. spy planes) are not flying overhead. Why would they hide where we are looking for them?"