-- The days of fighting Israel have ended for Diab Mohammed Ali, now the weary commander of Palestinian security forces in this unhappy city at the northern tip of the West Bank. Portly, with bristling gray hair, Ali made the transition from radical to mainstream more than a decade ago by joining a police system that has always drawn recruits from the young gunmen at war with Israel.

But Ali has little faith that the current generation of street fighters from the ruling Fatah movement can make the same leap into legitimacy, a process he is overseeing from a compound reduced to rubble nearly five years ago by Israeli forces. A job working for him has little to offer these days, he said.

Because the barracks are ruined, he sleeps in the primly made cot in the corner of his office. His meager arsenal allows one gun for every five officers in his fledgling force. Then there is the problem of the mind-set of the potential new recruits.

"These people are not used to a regular routine, a lifestyle we have in the military," said Ali, 61. "What are the intentions of these people? I don't really know."

Once the heart of the Palestinian uprising that began in September 2000, this city is now at the center of efforts by the Palestinian Authority president, Mahmoud Abbas, to merge armed groups across the West Bank into a police force capable of enforcing law and order in the Palestinian territories. Israeli leaders have tied Abbas's success in doing so in places like this city of 35,000 people to future military pullbacks from Israeli-occupied areas.

Senior Israeli military officials had been expressing hope that Jenin could be turned over to Palestinian authorities before the middle of August, when the evacuation of four nearby Israeli settlements is due to begin. Their logic is that the more Palestinian gunmen there are entering the police force and accepting its discipline, the fewer there will be to shoot at departing Israelis.

But so far, Israeli officials have accused Abbas of not doing enough to disarm the armed groups here. An argument is underway about how quickly to turn over Jenin and other cities in the West Bank, according to a senior Israeli officer. "The closer we get to disengagement and the fact we haven't seen anything done on the ground, I can say we have cold feet," the officer said.

Palestinian officials such as Ali expressed doubt that the hard young men of the uprising would trade the grim allure of guerrilla warfare for the drudgery of walking a beat, especially when polls show that about 60 percent of Palestinians favor maintaining the armed groups as a way to pressure Israel to leave the occupied territories.

"The success of their absorption depends upon the timing of the Israeli withdrawal from Palestinian cities, and the guarantees that will be given to these people that they will not be subject to arrests and killings," said Jibril Rajoub, Abbas's national security adviser.

The spring of 2002 was the high-water mark of the Palestinian uprising, or intifada. Israel sent armored vehicles rolling through the narrow streets of the Jenin refugee camp in some of the heaviest fighting of the intifada. Since then, most of the 400 demolished houses have been rebuilt, thanks to a $32 million gift from the United Arab Emirates. The streets are clean and the walls of the new homes mostly free of strident graffiti. Suicide bomb attacks originating in the area have stopped.

Zakaria Zbeida has been the unofficial sheriff of the camp for years. As Jenin leader of the al-Aqsa Martyrs Brigades, a military wing of Fatah, he commands more than 200 armed men. He and his fighters have signed up to join the police force, but none has actually done so. He remains reluctant to emerge from his fugitive life, which requires him to sleep days and stay vigilant at night when Israeli forces patrol the hillside refugee camp where he and 14,000 other people live.

"We've been the ones who have fulfilled the responsibility of the police force since the Israelis destroyed the headquarters and paralyzed the city," said Zbeida, 29, whose face bears permanent scorch marks from a bomb he was making that exploded prematurely. "The question is whether the Israelis will come and take me away in the middle of the night. There must be an agreement that they will completely withdraw from the city."

The other armed factions, the Islamic Resistance Movement, known as Hamas, and Islamic Jihad, which have rejected the political process with Israel, will remain largely outside the new security arrangement. "The idea of the Israelis was that, through this process, they will break the resistance and force us to hand over our weapons," said Abed Basit Haj, a Hamas spokesman. "This is something that Hamas could not take part in."

Zbeida said that even if he and his men were to join the police force, there would be no effort to disarm Hamas or Islamic Jihad, a key Israeli demand, without the groups' permission. "Nothing will be done by force," he said.

The streets here still come alive with gunfire occasionally. Sometimes it is the work of young men engaged in crime, notably car theft. Other times it represents a political challenge to the Palestinian Authority, whom many gunmen view as corrupt.

On the day Zbeida spoke about the authority of the al-Aqsa Martyrs Brigades, a group of men whom Palestinian authorities believe may be members of his group set fire to the car of a member of the Palestinian Legislative Council.

The next day, seven armed men arrived at the police station and shot one officer in the head, triggering exchanges of gunfire and a sweep of the refugee camp by the Palestinian police in search of those responsible.

Despite skepticism over the disarmament effort, the Israeli military has loosened its hold on the city during an informal cease-fire that is now nearly five months old. Palestinian police are allowed to carry light weapons and to patrol during daylight hours. Israeli officers notify Palestinian authorities before conducting operations inside the city after dark.

Sometime after Aug. 15, Israeli forces are scheduled to begin evacuating about 700 Israelis from the Ganim and Kadim settlements, which lie just a few miles east of Jenin across olive orchards and tobacco fields. Israeli military officials say the communities have begun taking nightly rifle fire.

Lt. Col. Fuad Halhal, the Israeli officer responsible for coordinating humanitarian issues in Jenin, said the best route now was to rely more on the Palestinian authorities. In some ways, he said, conditions have improved: militant demonstrations, anti-Israel rhetoric and attacks have all declined. Ali, the police commander, needs "more freedom to maneuver."

"It is far better that the Palestinians have as much control as possible in order to have a better grip on the ground during disengagement and the post-disengagement period," said Halhal, 39.

Ali predicts a tough job. "The situation here is very difficult," he said. "It's going to take a lot of work and sacrifice."

Researcher Samuel Sockol contributed to this article.

Diab Mohammed Ali, head of Palestinian security forces in Jenin, joined the police force more than a decade ago, a move he says young militants are reluctant to make.