By day, this northern West Bank community – once considered the Tombstone, Ariz., of the Palestinian territories – is the picture of calm, its old market bustling, farmlands in full production and a friendly policeman on every corner.

By night, however, it becomes vulnerable to raids and targeted assaults, not by the Palestinian militants who once ruled the streets, but by Israeli military patrols that invade the town and nearby villages at will.

The new Israeli government of Benjamin Netanyahu said last week it considered itself bound by the 2002 road map to Middle East peace. That plan calls for the Palestinian Authority to combat terrorism and establish security in the parts of the West Bank under its control.

With the help of U.S. and Canadian military officers, that's exactly what the Palestinian forces in Jenin have been doing.But all too often, twice in the past week alone, Israel troops have carried out night-time raids.

“I was notified Saturday afternoon that special [Israeli] units would be operating in the town that night,” said Colonel Radi Asedeh, the area commander of 2,000 Palestinian police and security forces. “I pulled my men out of the field,” he said. “I couldn't risk there being a clash.”

Three nights later they struck again, entering houses in Jenin and the nearby village of Qabatiya, apparently taking someone into custody and seizing a computer.

“Sometimes, they don't do anything but drive around,” Col. Asedeh said. “They only want to embarrass us.”

“There's no doubt these Israeli operations erode the people's respect for the PA forces,” said Colonel Chris Simonds, the commanding officer of a Canadian contingent of nine in the U.S. Security Co-ordinator's mission, headed by U.S. General Keith Dayton.

It was the USSC that trained the men who brought law and order to Jenin and who are determined to keep it that way.

“Before, the militants ruled the streets,” said Col. Asedeh, a 30-year veteran of Palestinian forces. “Not now.”

“The people longed for an end to the chaos,” he said. “They respect what we're achieving; the culture of violence has changed.”

During the intifada of the early 2000s, Israel estimated that a quarter of all suicide bombings inside Israel had emanated from the Jenin area, as had several military-style operations against Israeli troops and settlers.

That is history. “In the past year, not one bullet has been fired out of Jenin,” Col. Asedeh said.

Asked how he felt about help from the Dayton team, the 53-year-old commander folded his arms across his chest and said: “We're not embarrassed about our relationship with Gen. Dayton. We're grateful for the help.”

Col. Simonds, 50, a native of Kingston, explained that the Dayton group of 16 Americans, nine Canadians, three Britons and one Turk put the first battalion of 600 Palestinian presidential guards through a 19-week policing course in Jordan, provided further specialized training and sent the men into Jenin last May.

By October, the place was sufficiently peaceful for former British prime minister Tony Blair to tour Jenin's schools and declare the place “a model” for other Palestinian jurisdictions. By November, then-U.S. secretary of state Condoleezza Rice met with Palestinian Prime Minister Salam Fayyed in Jenin and called the town “a place of hope.”

In the past few weeks, that presidential guard battalion has returned to its base in Jericho, where it is housed in a facility designed by the Canadian contingent. The PA forces have been replaced in Jenin by the second battalion to complete the training courses.

As the success is solidified, the next battalions to graduate will be dispatched to other West Bank towns controlled by the Palestinian Authority, Col. Simonds said. “I expect the next group will go to Hebron.”

“Our goal is to assist the PA in carrying out its obligations under the road map,” explained Col. Simonds, the latest in a long line of Simonds to be officers in the Canadian forces.

“The Israelis won't allow the Palestinians to have an army,” he said, “so even though the security forces are structured like an army, they're not trained or equipped like an army. They're more like a gendarmerie.”

They have received training in urban patrolling, he said, “similar to what Canadian forces receive before going into Afghanistan.”

For their part, the Israelis did remove two nearby Israeli settlements in 2005 – part of the unilateral disengagement ordered by former Israeli prime minister Ariel Sharon that included the removal of Israelis from Gaza – and two more Israeli settlements to the south of Jenin.

Col. Asedeh, who was born in a village near Nablus, south of Jenin, was an Israeli prisoner of war in the early 1980s. He had joined the PLO forces in Lebanon just before Israel invaded in 1982 and, following his release in a prisoner exchange, he went on to bases in Algeria and Jordan, before entering the West Bank in 1996.

Assigned to the troublesome area of Jenin, he is considered one of the Palestinians' best commanders.

“Our success in Jenin came because of hard work,” he said, “and by winning the respect and confidence of the people.”

It also was because of his willingness to help the leading militants “climb down from their high perches,” Col. Asedeh said.

Zakariya Zubeidi was key among them. The former Jenin leader of the Al-Aqsa Martyrs Brigades, Mr. Zubeidi, now 33, was a local hero. He was one of the few Palestinian fighters not to have surrendered or been killed in the famous 2002 Battle of Jenin, in which more than 50 Palestinians and 23 Israeli soldiers perished. He escaped several other subsequent attempts to assassinate him.

By 2007, Mr. Zubeidi has said, he became disillusioned by the armed resistance and, with the help of Col. Asedeh – who assured Israel that Mr. Zubeidi would not be a threat – Israel granted him a conditional amnesty last year.

As part of the terms, he, along with a couple of dozen other former militants, must turn himself in to the PA security forces each evening and sleep in the barracks.

His compliance hasn't stopped the Israeli military from laying siege at times to his home, where his wife and two young children live.

“The Israelis are making it very hard for people like him to maintain their program,” Col. Asedeh said. “It won't take much for some of these people to go back to armed resistance.”

Such a development would jeopardize everything the forces have established in Jenin.

“It's almost like they want us to fail,” Col. Asedeh said.

The Israelis already insist on a curfew on Palestinian forces from midnight to 4 a.m., Col. Simonds said. But the army's incursions go even further. “Almost every night they conduct raids somewhere in Area A,” the Canadian commander said, referring to the area supposedly controlled by the Palestinian Authority.

“I understand the Israeli concerns,” Col. Simonds said. “They get information on what might be a terrorist plan and they have to act.”

“It would be better, though, if they gave the information to the PA and let them handle things,” he said. “But they're not willing to do this, at least not yet.”