As the government of Afghanistan struggles to re-assert its authority over the once lawless countryside, one warlord has brought stability and prosperity to his region, but at a price.

As the rule of the Taleban was nearing collapse one year ago, residents of Afghanistan's westernmost province were looking forward to the return of Ismail Khan. The former governor of Herat province was a hero, who had fought the Soviets and the Taleban. His legend grew, after he made a bold escape from a Taleban prison cell in 2000.

Ismail Khan is now back. And, indeed, he has brought prosperity and stability to Herat. The province is free of the kind of internecine fighting that remains the norm in much of the rest of Afghanistan. Roads are under construction, the water flows, and the electricity works.

But, as Alex Thier, a researcher on Afghanistan for the Brussels-based International Crisis Group, points out, all this comes at a steep price.

"The picture that that paints is a complicated one, because, on the one hand, you have the people of Herat, probably above everybody else in Afghanistan, enjoying a relative prosperity that they haven't seen for years," he said. "But, at the same time, they are also suffering under fairly severe political repression."

John Sifton of the group, Human Rights Watch, is the co-author of a sharply critical report on Ismail Khan's rule in Herat. He says, life there today is not much different than it was under the Taleban.

"Ismail Khan is running a mini-state in the west of Afghanistan, and he's essentially running it as a tyrant. He's stifled all the local opposition," Mr. Sifton said. "He's torturing and beating his opponents, as well as just ordinary criminal detainees. And, most worrisome, he is implementing many Taleban-era restrictions on social life, especially with respect to women."

To many observers, the change in Ismail Khan's rule is inexplicable. One year ago, his reputation as a moderate and progressive leader was such that it prompted Michael Griffin, author of a highly respected book on the Taleban, to declare in an interview that Ismail Khan had what he described as an "unbloodied reputation," and that the Herat leader represented what Mr. Griffin called a "vanished golden age" in Afghanistan.

Some wonder if Mr. Khan underwent some kind of transformation during his exile in Iran, where he fled after his daring prison escape.

Certainly, Iran has played a major role in Herat's renaissance. Tolls and taxes collected from cross-border trade have allowed Mr. Khan to pay his civil servants, without outside help, something that the central government in Kabul has not been able to do. Analysts say Iran is pouring funds into Herat for public works projects, such as road construction, just as the United States and Europe are starting to do in other parts of Afghanistan.

Mr. Their of the International Crisis Group says that, while all of this is good, the danger is that warlords like Ismail Khan are building up autonomous power, making it harder for the still-shaky central government in Kabul to assert authority elsewhere in the country.

"Because Herat has a leader who is very much going, or continuing to go, his own way at the moment, and because Herat is pulling away from much of Afghanistan economically, it may actually inspire a temptation on the part of people like Ismail Khan to keep themselves from joining a national government in Afghanistan, because the benefits of maintaining control over the territory that they now control are so much greater than what they would benefit from joining the central government," Mr. Their said.

Much of the power Ismail Khan and his fellow warlords enjoy was a byproduct of U.S. anti-terrorism efforts in Afghanistan. U.S. troops and intelligence agents distributed cash and weapons to the warlords to enlist their help in rooting out al-Qaida and Taleban forces. Now, U.S. military officials have recently said that troops stationed in Afghanistan will be refocusing many of their efforts on reconstruction projects, in the hope that Afghanistan can be stabilized by the shovel instead of the gun.