TASHKENT, Uzbekistan - Corruption, repression and economic hardship have fueled such widespread discontent here that the entire country is on the brink of unraveling, and many fear that with the slightest effort the Taliban of neighboring Afghanistan could set off an explosion in Uzbekistan that would reverberate throughout Asia.

Uzbekistan is the keystone to Central Asia, a region of former Soviet republics rich in oil and gas and hobbled by poverty. If Uzbekistan falls apart, all of Central Asia will follow. And if Central Asia spins out of control, that will likely draw its two big neighbors - Russia and China - into the fray.

Uzbekistan has been struggling with two separate Islamic movements. An underground political party in the nation's cities seeks a peaceful transformation into an Islamic republic. A small but wily armed guerrilla movement - which has the direct backing of the Taliban and uses bases in Afghanistan - seeks to overthrow the government by force.

Through indiscriminate arrests, torture and killings, against a backdrop of economic mismanagement, the regime has managed to create serious opposition forces where once none existed. Hostile to even mainstream Islamic teaching, it has been unable to counter extremist interpretations of the Quran within the opposition - interpretations that glorify violence and demonize the infidel West.

The government has been considering this week whether to make air bases available to U.S. forces gathering for an attack on Afghanistan. But a representative of the anti-Taliban Afghanis warns that the Taliban could cross the Amu Darya river into Uzbekistan almost at will, despite extensive minefields along the border. A quick victory in a battle against demoralized and ill-equipped government forces, some say, could lead to the disintegration of the country.

"And yet, the main problem is not from Afghanistan but from a very unstable situation inside Uzbekistan itself," says Vitaly Ponomaryov, head of the Central Asian program of the Memorial Human Rights Center in Moscow.

Islam Karimov was the last Communist Party leader of the Soviet republic of Uzbekistan, and he effortlessly turned himself into president of the nation of Uzbekistan in 1991. His country had little of the natural resources to be found elsewhere in Central Asia, but it was the most populous country in the region, it was geographically central, and its agriculture should have provided the foundation of a prosperous economy.

After police opened fire on a student demonstration in January 1992, the Karimov regime shut down the universities and spent the next several years stamping out a nascent democratic opposition.

Karimov pointed to a clan-based civil war in Tajikistan next door, claimed his opponents were Islamic radicals who wanted to bring the war to Uzbekistan, and declared that this justified the crackdown. The democrats were scattered. What caught the government off guard was the emergence of a genuinely Islamic, anti-democratic movement.

For two years, Uzbek fighters based in Tajikistan and Afghanistan have made forays into villages across the border and held them until driven off by the ragged Uzbek army. The attacks underscored the weaknesses of a regime more intent on subjugating its people than on being able to carry on a shooting war.

The Islamic fighters have gained financial support from Uzbek exiles in Saudi Arabia and training from the Taliban.

Another Islamic movement, called Hizb ut-Tahrir, has sprung up in the cities, espousing the nonviolent creation of an Islamic state. An international group founded by Palestinians in 1952, it has underground branches in several of the Central Asian countries but is most active in Uzbekistan.

Legally banned throughout the region, it has appealed to people who are eager for stability and discipline. The government has responded by cracking down on mosques and arresting thousands suspected of harboring too much zeal for Islam.

In a country of slightly more than 20 million people, rights advocates put the number of those arrested at 100,000, perhaps more.

The result has been widespread discontent. In July, an estimated 600 women demonstrated in Tashkent and Andijan to protest the imprisonment of their husbands and brothers as Islamic extremists. The police arrested many - including any woman in the vicinity wearing a head scarf, one witness says - and beat several.

"Two hundred women are hardly going to overthrow the city government," says Vasilya Inoyatova, a dogged human rights campaigner. But the authorities were afraid, she says, that if they didn't crack down, others would soon join them.

The Islamists' popularity is not hard to fathom, says Ghulam Sakhi Ghairat, an official in the embassy of the anti-Taliban Afghan forces in Moscow. The people of Central Asia are "very ready" to listen to anyone who offers retribution against corrupt officials and answers to life's questions, he says. Their anger, he says, is like a dam ready to break.

"But this is not a clash of civilizations," Ghairat says. "I don't think the Muslim is very, very dangerous. What is important is the poverty."

Not all unrest is religious. Villagers in Duslik blocked the highway from Tashkent on June 26, unhappy that they hadn't had gas for three years or drinking water for five years, despite government promises, and that they hadn't been paid in months. The government turned on the gas and paid the back wages - which stopped the protest but demonstrated to many who had been cowed by a decade of harsh repression that disobedience can bring results.