Osama bin Laden's presence brings Afghanistan's ruling Taliban a trove of donations from a global network that has helped keep the cash-starved militia in power, intelligence experts say.

While a U.S. attack would be costly for Afghanistan, the ruling Taliban would likely lose an important source of income if it forces bin Laden out.

Bin Laden takes in millions of dollars in contributions from Islamic supporters in the Arab world, which in turn are used partly to fund Afghanistan's leaders, intelligence experts say.

With a personal fortune estimated at $300 million, bin Laden funds a global network of as many as 3,000 Islamic militants and also supplies highly trained fighters for the Taliban's war against a northern-based opposition alliance.

Bin Laden's "been a major economic force, attracting millions, certainly tens of millions of dollars in external support to Afghanistan," said Jonathan M. Winer, the deputy assistant secretary of state for international enforcement during the Clinton administration.

In one instance, a Taliban commander in Afghanistan told The Associated Press he had taken $250,000 supplied by bin Laden to Kunduz province in the north to finance the Taliban war effort there.

In another, an airport manager in the eastern city of Jalalabad told AP that bin Laden operatives arrived toting gym bags and briefcases full of cash. The men carried cards from the Taliban leadership ordering officials to give them safe passage, said the manager, who goes by the single name Abdullah.

The fighters bin Laden controls have spread across the globe to support Islamic rebellions from Chechnya to Albania to the Philippines, and supporters of those struggles have funneled money back to him.

"That pan-Islamic military support has caused people who support that kind of action to contribute money to bin Laden, which in turn flow to the Taliban in part," Winer said.

The Taliban's overseas assets have been frozen and they lost another source of income when they bowed to international demands to eliminate the country's huge opium crop, the raw material used to make heroin. The result has been devastating for farmers and day laborers who depended on poppy production for their survival.

Like a landlord reluctantly moving to oust a valuable tenant, Taliban leaders urged bin Laden on Thursday to voluntarily leave the country. President Bush immediately rejected that, ordering the Taliban to turn him over.

Bush also called on the religious militia to close all terrorist camps in Afghanistan, not just those directly tied to bin Laden, the No. 1 suspect in the Sept. 11 suicide jet attacks on the World Trade Center and the Pentagon.

Bin Laden is a hero of Afghanistan's successful war with the Soviet Union, and if the Taliban force him to leave, they could be branded hypocrites among the radical militants they depend on for financing and other support.

Still, if they allow him to remain, it could mean a massive U.S. attack -- one that might oust them from power.

"The Taliban leadership are beginning to see him as more of a liability than as an asset," said Peter Chalk, an analyst specializing in terrorism and national security for Rand Corp. based in Washington.

It was because of pressure from the United States and North African countries that Sudan forced bin Laden to leave in 1996. The global community also persuaded Libya to give up two intelligence agents in 1999 who were suspected in the bombing of Pan Am Flight 103 over Lockerbie, Scotland. U.N. resolutions had barred air travel to and from Libya, and imposed other sanctions.

Washington is hoping it can duplicate that success with the Taliban. But impoverished Afghanistan may have less to lose than other renegade countries, and international sanctions so far have not moved the Taliban.

"He continues to pay rent and his lease hasn't expired," said Frank Cilluffo, senior policy analyst at the Center for Strategic and International Studies, a Washington think tank.