Now, American commanders say protecting the country's fragile new democracy, reviving its economy and keeping Taliban militants on the run are the priorities, though tracking the cold trail of bin Laden and other al Qaeda leaders remains the focus of intelligence efforts.
Spies, informers, electronic listening devices and surveillance from the air all belong to the U.S. arsenal. However, American officials acknowledge that videotapes featuring a sprightly looking bin Laden — released days before the Nov. 2 election in the United States — and his deputy Ayman al-Zawahri, have yielded no clues to their whereabouts, even though one was delivered to a TV channel in Islamabad.
"They're pretty sterile in terms of intelligence value," Maj. Gen. Eric Olson, the operational commander of U.S. forces here, told The Associated Press.
Despite initial high expectations on the other side of the border, Pakistan's yearlong crackdown against foreign militants near the tribal town of Wana also has yielded no trace of bin Laden or al-Zawahri.
"We have no specific indication that they are in the Wana area or really any other location" in the region, Olson said. "But the hunt goes on."
American generals have had three years to rue how the suspected mastermind of the Sept. 11, 2001 attacks slipped away from Afghan and U.S. troops near the Tora Bora caves of Afghanistan's eastern mountains as the regime of his Taliban protectors crumbled that December.
French Defense Minister Michele Alliot-Marie, who has special forces patrolling farther south, claimed last month that bin Laden narrowly escaped an American operation as recently as mid-2003. But there is no firm evidence anyone has picked up his trail since.
Interviewed at Bagram Air Base, nerve-center of the 18,000-strong force he helps command, Olson said this week that his immediate goals were preventing insurgents from mounting a "strategic surprise" with an attack on President-elect Hamid Karzai's Dec. 7 inauguration, and keeping them on the defensive ahead of April parliamentary elections.
Still, American commanders have slowly diluted their focus on combat operations against Taliban militants to take in more of the kind of nation-building that the Bush administration was once wary of.
Lawless provinces in the south and east are now dotted with "provincial reconstruction teams" designed to help the Afghan government regain a grip on the countryside while squeezing better intelligence from ordinary Afghans in return for building wells and clinics.
Olson said running down bin Laden and his cohorts was still the focus of American intelligence efforts here. "That's the main effort, no doubt about it."
The general said al Qaeda cells could still be in Afghanistan — Kabul has seen four deadly suicide attacks this year — and have encountered foreign fighters on several recent operations.
On Nov. 21, U.S.-led troops mounted raids on suspected al Qaeda compounds in Nangarhar, not far from Tora Bora. The U.S. military said "several Arab fighters" were among suspects killed or detained.
Another raid targeting an unidentified "al Qaeda facilitator" a week later provoked riotous protests after the suspect's wife was taken into custody, a breach of tribal honor codes.
Olson said the chief suspect, who escaped, is only a "medium-value target" in Nangarhar, but that this kind of operation was now the military's best hope in the hunt for bigger fish.
Intelligence gleaned from such captives can help "piece together a story that leads you to more specific locations for the senior leaders," he said. "I honestly believe that that's the way that Osama bin Laden and al-Zawahri are eventually going to be located."
Despite the drain on resources posed by Iraq, the number of special forces in Afghanistan has held "steady," at an undisclosed level, Olson said.
He said he was redistributing those troops along the border in an effort to catch militants trying to slip back and forth from safe havens on the Pakistani side.
To that end, cooperation with Pakistan is vital.
U.S. and Afghan officials have praised Islamabad for its bloody operations around Wana, the main town of the lawless Waziristan region, where fierce resistance earlier this year fueled speculation that a high-value target — possible al-Zawahri — was cornered.
If he was, he escaped. Pakistani commanders now say they don't believe any of al Qaeda's top brass are in the region.
Maj. Gen. Niaz Khattak, commander of Pakistan's military operations against al Qaeda-linked fighters in South Waziristan, has predicted the fiercely autonomous area will be pacified by year's end. But he says there is no sign of bin Laden and that most of the foreigners still in the region are low-level fighters.
Khattak said only a few foreign militants have been captured alive. He estimated that among the nearly 300 militants killed in the past nine months, about 100 were foreigners — principally Uzbeks, Chechens, Tajiks and Afghans.
"If intelligence comes by, we will certainly pursue it. If you're asking whether [bin Laden] is here or not, there's no indications of his presence," he told reporters on a recent trip to the region.
"There might be some terrain where nobody has been able to go. But we have intelligence, and there's no way such high-value information would remain hidden for such a long period of time," he added. "After all, there should have been a rumor if nothing else."