The Palestinian president has chosen the West Bank's most chaotic city to show he's in control, winning U.S. praise Thursday for beefing up his security forces here as part of an attempt to reassure Israel that he can implement a future peace deal.

However, Mahmoud Abbas' campaign to disarm hundreds of militants in Nablus has had mixed results.

A former fighter in Abbas' Fatah movement gave up his weapon in exchange for amnesty, but is still teaching his 6-year-old son to shoot an M-16. Dozens refuse to disarm for fear of being defenseless against Israeli raids. And the rival Hamas appears to have hidden most of its arms.

Success of the law-and-order campaign is crucial for U.S.-led peace efforts, including Washington's plan to hold a Mideast conference in Annapolis, Md., later this year.

Israel insists Abbas' security forces don't control the West Bank, saying that erodes its ability to make concessions. Palestinian security chiefs say Israel undermines their crackdown by restricting the movement of police and preventing them from getting enough weapons and ammunition.

Abbas picked unruly Nablus, the West Bank's second-largest city with 170,000 people, as his testing ground. Since the outbreak of the second Palestinian uprising in 2000, the city has been a stronghold for Hamas and Fatah gunmen as well as vigilantes who rob and blackmail residents.

Many suicide bombings and shooting attacks on Israelis were launched from Nablus, and for seven years the city has buckled under severe Israeli travel restrictions, enforced by a ring of army roadblocks.

Under the security plan of Abbas and his prime minister, Salam Fayyad, 3,000 Palestinian police officers in Nablus were gradually ordered back to their jobs in recent months, after many spent most of the uprising off the streets in fear of being targeted by Israel. The governor of the Nablus district, Jamal Muheisen, said 500 more officers will be deployed in coming days.

The U.S. security coordinator with the Palestinians, Lt. Gen. Keith Dayton, toured Nablus on Thursday and praised the Palestinian efforts after meeting with the local security chiefs.

"This is where the Palestinian state will get its first real test," he said. "When you succeed in Nablus, it will send a message throughout the West Bank and it will send a message to your neighbors that you're serious about law and order and that you can do the job."

Palestinian officials said they need more guns, ammunition and freedom of movement, all of which require Israeli approval. Abdullah Kmeil, the Nablus intelligence chief, said there is only one rifle for every 10 officers, leaving security forces outgunned by militants.

Congress has approved $80 million for strengthening Abbas and his security forces, and the Palestinian leader promised to rebuild security compounds destroyed by Israel in several years of fighting.

The Nablus governor said Israel should halt its frequent arrest raids in Nablus, which make it harder for the Palestinian authorities to persuade Fatah gunmen to disarm. But the Israelis say they can't take any chances.

"The Palestinian leadership today is not capable of implementing its obligations to rein in these groups and in the absence of this capability, Israel must act," said Foreign Ministry spokesman Mark Regev.

On Wednesday, Fatah gunmen claimed responsibility for a drive-by shooting in which an Israeli soldier was seriously wounded while waiting at a bus stop outside an Israeli settlement near Nablus.

Israeli analyst Yossi Alpher said the Palestinian security forces simply don't have enough clout to collect all weapons. "I don't think they can succeed," he said.

On the other hand, human rights activists contend that Abbas' security forces have gone too far in their crackdown, especially on Hamas activists.

Amnesty International said in a report this week that some 1,000 Hamas members were rounded up in the West Bank after Hamas' violent takeover of Gaza in June and that many of the detainees were mistreated.

Kmeil defended the campaign as a success, saying Hamas "is in a state of confusion" in the West Bank. However, finding Hamas' weapons is proving to be difficult.

Hamas activist Saad Khodariyeh, a 29-year-old school bus driver in Nablus, said he was recently held 26 days on suspicion of hiding an AK-47. He said that during interrogation, his hands were tied behind his back and hooked to a wall, and that his leg muscles eventually tore and got infected.

Investigators never found the suspected weapon, which Khodariyeh said he never possessed.

Sheik Maher Kharas, a prominent Hamas member, said the group is simply waiting. "We can hide, or keep the weapons buried under the dirt for a while," he said. "But then we will rise again."

The Palestinian Authority has also shut down more than 100 Hamas-linked charities and outlawed Hamas' military wing. The group's political leaders are keeping a low profile.

Abbas' security forces have made sporadic efforts to disarm Islamic Jihad, a small, violent group bent on Israel's destruction. Last month, Islamic Jihad militants shot and killed a Palestinian policeman in the northern West Bank town of Jenin after he stopped their car to check for registration papers.

Even gunmen loyal to Abbas are not changing their ways easily.

"I can't give up my weapons, because the Palestinian Authority can't protect me (against Israel)," said Mehdi Abu Ghazaleh, a leader of the Al Aqsa Martyrs' Brigades, a violent Fatah offshoot.

Some 200 Al Aqsa gunmen exchanged their weapons for Israel's offer of amnesty during the summer, but some keep a spare, just in case.

Mahdi Maraki, 31, handed over his M-16 in the amnesty deal, yet is teaching his two sons how to shoot. He displayed video on his mobile phone showing his chubby-cheeked 6-year-old boy spraying M-16 fire into the air.