In an interview three years ago, former National Security Adviser Zbignew Brzezinski answered a question by asking one: "Which is more important in world history? The Taliban or the fall of the Soviet Empire? A few over-excited Islamists or the liberation of Central Europe and the end of the Cold War?"

The answer that Brzezinski thought so obvious back then seems less so today, a week after the most spectacular terrorist attack in history. Last week, the bill came due on the U.S. decision, taken more than two decades ago, to arm and finance a fundamentalist jihad, or holy war, against the Soviet Union's invasion of Afghanistan. The U.S. must now launch a war against the sophisticated and well-equipped terrorist network that it helped spawn.

The Taliban's rise from an obscure organization born in the religious schools of Pakistan's refugee camps on its Afghan border to become sponsors for one of the world's most extensive training grounds for global terrorism is the result of an extraordinary confluence of regional power struggles, high finance, religious zealotry, international neglect and fortuitous timing.

There are few places on Earth where people have lived in greater misery for more years than Afghanistan. One of every four children dies before the age of 5, life expectancy is about 43 years, infant and maternal death rates are the second-highest in the world, only 12 percent of the population has access to safe drinking water, and barely 30 percent of the men and 15 percent of the women can read or write.

Its people have been bombed, raped, tortured, slaughtered, looted and uprooted by two decades of war. Its lands are some of the most densely mined in the world. Its roads, irrigation systems and other infrastructure have been devastated by war and poverty. In one of its most recent reports, the United Nations described the situation in Afghanistan as "a horror."

In the nearly decadelong war against Soviet forces in the 1980s, Afghan tribes and ethnic groups that had been feuding for centuries joined together against the Soviet army, bolstered by training, equipment and money funneled through Pakistan by the CIA.

Even before Soviet tanks rolled into Kabul in December 1979, Brzezinski recognized the trouble-making potential of a few well-armed religious zealots. During the summer of 1979, he persuaded President Carter to sign a secret directive to supply covert aid to a budding Mujahedeen movement.

From a trickle to a flood

What began as a trickle would soon turn into a flood of arms and money. The CIA took responsibility for acquisition and shipment of weapons. Much of the hardware was purchased on the black market from Soviet bloc countries, although one of the most effective weapons in the Mujahedeen's arsenal would turn out to be U.S.-made Stinger missiles. They used the missiles to shoot down hundreds of Russian helicopters.

Pakistan's Interservices Intelligence Directorate, working with the CIA, was in charge of recruiting and training the guerrillas.

The directorate cast a wide net. Religiously inclined young men from North Africa, the Persian Gulf region and Palestinian refugee camps that fester across the Middle East signed up for the jihad. One of the early recruits was a young, very wealthy Saudi construction tycoon: Osama bin Laden.

Money for the undertaking also poured in from the anti-communist Saudis.

The CIA's jihad, well under way within a year, was warmly embraced by the Reagan administration when it took office in 1981. Afghanistan was becoming the Soviet Union's Vietnam. Over the next eight years, the relentless hit-and-run tactics of the Mujahedeen, or holy warriors, would demoralize the Soviet Union and sap its military strength.

When the Russians gave up and pulled out in 1989, the Mujahedeen recruited from different Arab countries began to trickle back to their homelands. The end of the war coincided with a surging Islamic militancy that had spread from Iran and Afghanistan to almost every corner of the Muslim world. Veterans from the conflict saw themselves as the vanguard of a new revolutionary order. The ruling establishment saw them as dangerous and destabilizing elements.

Egypt spent the better part of the 1990s in a brutal crackdown against an Islamic insurgency led by veterans from the Afghan war. Among the horrors of this conflict was the 1997 massacre of 58 foreign tourists in Luxor.

In Algeria, more than 100,000 people have died in a war between a corrupt government dominated by the military and an Islamic movement led by Afghan war veterans.

The 1993 attack on the World Trade Center in New York, the car bombs in Moscow linked to Chechen rebels, the kidnappings of foreigners by the Abu Sayyaf group in the Philippines — all share a common Afghan pedigree.

Soon after the Islamic guerrillas forced the Soviet Union to withdraw in 1989, the coalition of victorious factions disintegrated. Within three years, the country's prime minister and defense minister organized different armies and were shelling each other and raining bombs and missiles on the citizens of Kabul. The country was carved up by warlords with their own armies and police forces, most of which routinely robbed and killed civilians belonging to ethnic groups or tribes different from their own.

By 1994, Afghanistan was in chaos, its citizens fleeing the country by the hundreds of thousands.

Born in the refugee camps

Young Afghans who had spent most of their lives in refugee camps in Pakistan near the Afghan border watching their country implode became increasingly disillusioned and radicalized in the conservative religious schools that mushroomed in the dismal camps. Slowly they began filtering back into Afghanistan and rallied around a mysterious, one-eyed religious leader, Mullah Mohammad Omar, now believed to be about 42 years old, who had fought against the Soviets and espoused a return to law and order in his country.

In the villages near the southern city of Kandahar, Omar and his small but growing band earned a reputation for standing up to corrupt warlords, rescuing local village girls from soldiers who kidnapped them for sex, and reopening roads that were controlled by local commanders demanding exorbitant "tolls" from anyone who passed.

When a 30-truck convoy from Pakistan was nabbed by an Afghan warlord seven years ago as it rumbled across the southern Afghanistan desert, a small band of Islamic militants came to the rescue. They called themselves the Taliban, literally "the students," and they freed the convoy, chased the hijacker into the desert, shot him dead and hung his body from the barrel of a tank for all to see.

That episode cemented a critical relationship that led Pakistan, already burdened by 2 million war refugees, to nurture, finance and arm the strict Islamic militia.

Lavishly funded by the equally puritanical Saudis; armed, trained and organized by Pakistan's intelligence directorate, the Taliban gradually took control of Afghanistan.

Evidence of U.S. involvement at this point is sketchy. All that can be said with certainty is that the Clinton administration, failing to recognize the danger signs, did nothing to curb Saudi or Pakistani support for the Taliban.

The Taliban won most of their early victories when local warlords simply surrendered, weary of years of fighting. But the Taliban's battles became increasingly difficult as they launched assaults against larger cities and territories controlled by the major fighting forces in the country.

Bin Laden's odyssey

Osama bin Laden, finding himself under house arrest in Saudi Arabia for criticizing the monarchy as too acquiescent to the United States, fled the country in 1991. He went first to Afghanistan, and then to Sudan.

In May 1996, bin Laden was exiled from Sudan under international pressure for his alleged terrorist activities and was invited to Afghanistan by the Taliban. He reportedly gave the Taliban $3 million to boost its flagging military efforts. With bin Laden's money and military advisers, as well as continued assistance from Pakistan, the Taliban captured Kabul, the capital, as well as the country's second-most-important city of Jalalabad, and by winter declared themselves in control.

The Taliban have since reaped thousands of fighters and tens of millions of dollars in cash and equipment from bin Laden.

In turn, bin Laden has won increasing influence over a movement that's allowed him to turn Afghanistan into his personal training center for terrorists who, according to Western experts and intelligence estimates, are then dispersed across the globe.

A pariah state recognized by only three world powers — Pakistan, Saudi Arabia and the United Arab Emirates — the Taliban movement now operates a broad financial support network that the West has so far been unable to terminate. It's filtered through hundreds of legitimate business and front organizations in Pakistan, Saudi Arabia and across the Islamic world, according to U.S. and United Nations documents and Pakistani military, intelligence and news reports. It is also widely believed that the Taliban movement is still heavily funded by a network of wealthy Saudi businessmen, some in alliance with bin Laden.

Pakistan's intelligence agency keeps close tabs on the Taliban, although the government of Gen. Pervez Musharraf has tried to distance itself from some of the more odious aspects of the regime next door.

"Now Pakistan is stuck with the Taliban government," said Ahmed Rashid, a Pakistani journalist who has recently written an extensively researched book on the Taliban. "Despite warnings that it has become a monster, the military has not been listening."

At first the Taliban were welcomed by the Afghans. At least the Taliban seemed honest, if perhaps a little overly zealous. But soon the group's true intentions became clear — a fanatically "pure" Islamic society.

Since assuming control over 90 to 95 percent of Afghanistan, the Taliban have imposed the strictest form of Islam in the world: Women are required to wear head-to-toe veils, aren't allowed to work and after puberty aren't allowed to attend school; men must wear long beards or go to jail until their whiskers have reached sufficient length; television, movies and the Internet are banned. Under the Taliban's harsh judicial code, apostates are beheaded and "sodomizers" buried alive.

Brutal as their predecessors

In their efforts to control the country, the Taliban have become as brutal as their predecessors, slaughtering civilians, burning houses and destroying crops in the villages and towns they have conquered, according to human-rights investigations. As a result, the Afghan people have become far less supportive of the ruling government, and the Taliban have found it difficult to recruit native Afghan men into their ranks.

Again Pakistan and bin Laden have helped fill the void. Pakistan allowed recruits from its religious schools and religious political parties to fill the Taliban ranks, and bin Laden has created and funded an Arab force attracting Saudis and others, according to numerous military, U.N. and human-rights reports.

And in the past three years, with the urging of bin Laden, the Taliban have opened their training camps to would-be terrorists from throughout the Middle East, Africa and Asia.

Some observers, including Rashid, believe bin Laden has played a major role in the increasing radicalization of the Taliban, and may have been the motivating force behind their destruction of two ancient Buddha statues earlier this year and the recent arrest of foreign aid workers on charges of spreading Christianity.

Bin Laden is also the suspected mastermind behind the assassination last week of the Taliban's chief rival, Ahmed Shah Massoud, who headed the Northern Alliance, a loose group of onetime warring ethnic commanders who have joined forces against the Taliban, much as they did against the Soviet forces.

Now many military observers believe the Northern Alliance, which is supported by Iran and Russia, could crumble, giving the Taliban control of the entire country.