The U.S. military campaign in Afghanistan appears to be a success so far, but the man it is ultimately aimed at is still on the loose.
Osama bin Laden, mastermind of the Sept. 11 terror attacks, has eluded capture and death even as his Taliban hosts find their regime crumbling in disarray.
Bin Laden is believed to be on the move in the shrinking but still difficult parts of Afghanistan that Taliban forces control.
So, as America sharpens the focus on the war's primary target, special operations troops are questioning Taliban defectors and prisoners, dangling millions in reward money and hoping for a communications slipup. And U.S. warplanes are aiming more bombs at mountain hideouts and caves where bin Laden might try to disappear.
Bin Laden, an expert in guerrilla warfare, has plenty of those remote caves and mountain tunnels _ and enough friends and supplies along the Pakistani border _ to make the chase difficult.
"We still have a ways to go," Defense Secretary Donald Rumsfeld warned on Wednesday.
Reports on bin Laden's whereabouts are all over the map, but most agree that he and Taliban leader Mullah Mohammed Omar are still in Afghanistan.
The Associated Press, citing intelligence officials, says the two aren't believed to be together. Knight Ridder reports that intelligence officials think bin Laden is hiding in the mountains of southern Oruzgan province, in the center of the country. Others say he could be in mountain camps in the east near Jalalabad.
British Foreign Secretary Jack Straw, during a visit to the United Nations on Wednesday, said bin Laden and his top lieutenants are believed to be near Kandahar.
A Taliban official said Wednesday only that Omar and his "guest" bin Laden were "safe and well."
The Taliban also remained adamant in its refusal to turn bin Laden over to the United States for the murder of thousands of Americans with the crashing of hijacked planes into the World Trade Center towers and the Pentagon.
"There is no change in our position on the issue of Osama," Taliban spokesman Mullah Abdullah said in a statement to the Pakistan-based Afghan Islamic Press.
The amount of help bin Laden gets from his past supporters is key.
Afghan fighters have a history of retreating from cities but then waging effective guerrilla warfare in mountains for years afterward, essentially thwarting an enemy's larger goals, Charles Fairbanks, a central Asia expert at Johns Hopkins University, told the AP.
"Particularly if they fled to the east, that's a very difficult situation," Fairbanks said. "They have so many sympathizers in Pakistan, and Pakistan really has no control of the situation there."
Such supporters could keep bin Laden and Omar supplied with food, guns and hiding places, said Andrew Hess, an expert on Pakistan and Afghanistan at Tufts University.
Wherever bin Laden is, however, it's unlikely he will try to leave the country. Such movements could expose him to capture.
Defectors and prisoners are probably the best hope for information on where bin Laden is now.
According to the AP, which cited a former senior U.S. intelligence official with experience in South Asia, even rumors or hints _ about something such as a recent supply run to a cave, for example _ could prove a breakthrough.
In addition, "It may very well be that money will talk at some point," Rumsfeld said, referring to the millions in reward money the United States has offered.
Or, Taliban troops and commanders on the run might take fewer precautions with radios and phones, allowing U.S. eavesdropping aircraft to pick up communications and thus get hints to bin Laden's location.
Knight Ridder, citing a senior intelligence official, reported that Northern Alliance troops seized a hastily abandoned house that appeared to have been occupied occasionally by bin Laden or some of his senior lieutenants and contained a wealth of al-Qaida documents.
After a classified intelligence briefing, the top Republican on the Senate Intelligence Committee said Wednesday that the situation "does not bode well for Osama bin Laden in Afghanistan or anywhere else he might run to."
Sen. Richard Shelby, R-Ala., said U.S. intelligence "has improved a lot" in Afghanistan, the result of hard work by U.S. agencies as well as the military gains. "As you take over territory, you see more people that you had no access to before," he said.
Another way to locate bin Laden would be to flush him out of hiding.
The United States is bombing areas in the south and in the east, especially around Jalalabad, where bin Laden is known to have hideouts. "Bunker-buster" bombs can dig under the surface and explode in a tunnel. Fuel-air explosives can produce tremendous heat and suck out a cave or tunnel's oxygen.
If necessary, U.S. ground troops are prepared to fight a guerrilla action in the caves and tunnels, Rear Adm. John Stufflebeem, a Pentagon spokesman, said Wednesday.
The original attack plan written by Gen. Tommy Franks, commander of U.S. Central Command, achieved its objective _ the collapse of the Taliban _ so suddenly that the entire approach to Afghanistan needs to be rethought, according to defense officials who discussed the matter with the AP.
Just last week Franks was under fire from critics who said he was moving too slowly against the Taliban. Then the crossroads city of Mazar-e-Sharif fell and the rout was on.
Franks' new plan has yet to be written and must be approved by Rumsfeld and President Bush. Among the main issues, however, are how to pursue bin Laden and his key lieutenants, the extent to which Afghan opposition groups will continue to be enlisted as American proxies on the ground and the number and kind of U.S. forces needed to establish military operations at air bases inside Afghanistan. These bases could be used as launching points for commando raids against al-Qaida hideouts, or for air operations.
If the Taliban leadership crumbles entirely, locating bin Laden may not be necessary.
Frederick Starr, director of the Central Asian Institute at Johns Hopkins University, told Hearst Newspapers that the majority of Afghans have disdain for bin Laden and the Arab fighters who surround him and are among his most loyal troops. They were invited in by the Taliban after 1996.
"Once people feel that the core of the Taliban is out of the picture, the Afghans themselves will find and destroy him. They'll also finish off the Arabs who are protecting him," Starr said.
_ Information from the Associated Press, Knight Ridder, Cox News Service and Hearst Newspapers was used to compile this report.