As the highest-ranking commander of nearly 8,000 Palestinian security troops, Maj. Gen. Diab Ali is accustomed to being top gun. But the salutes often stop when he leaves the military base and travels through the West Bank.

Experience has taught the general to leave his gun behind and trade the uniform for civilian clothes, lest some young Israeli checkpoint guard decide to hold him for questioning or block his way.

"It avoids problems," said Ali, commander of the National Security Forces of the Palestinian Authority.

It's a small -- some might say demeaning -- example of the challenges facing Palestinian security forces as they struggle to find a balance between operating under Israeli limits on their control in the West Bank and maintaining legitimacy in the eyes of their own people.

By most accounts, the recently reformed Palestinian security forces are more professional and disciplined than ever. Troops have won praise for restoring law and order to several West Bank cities, including Nablus and Hebron.

But after three years of U.S.-funded training and recruitment, the security forces are at a crossroads, Palestinian leaders say.

A shortage of weapons, money and authority, and continuing Israeli military incursions into areas that are supposed to be under Palestinian control, are threatening to turn public pride and confidence into distrust and derision, Palestinians say.

Ali said his forces have held up their part of the bargain by stopping suicide attacks and reducing violence against Israeli settlers.

Last month, Palestinian forces exposed a West Bank militant cell preparing to launch a rocket into Israel. A year ago, Palestinian troops tamped down West Bank demonstrations spurred by Israel's 22-day assault on the Gaza Strip.

Israelis and international observers say that's exactly the kind of work Palestinian security forces should be doing. But for some Palestinians, who still view Israel as the enemy, there's a fine line between cooperation and collaboration. Already some critics dismiss the Palestinian forces as "Israeli subcontractors" or an "occupier's army."

"Israelis have turned us into the guards of their own kingdom," said Abdul Sattar Kassem, a Palestinian political science professor at An Najah National University in Nablus.

Palestinian Authority Prime Minister Salam Fayyad, who says an independent security force is one of the linchpins of a future Palestinian state, warned that Palestinians are losing patience with Israel's reluctance to hand over security responsibility. According to Fayyad, the current stalemate is putting "the whole enterprise at risk."

Israelis acknowledge the improvement but say Palestinian forces are not yet ready to assume control of the West Bank. Without Israeli military support, they say, militants would overrun the authority's forces, as they did in Gaza in 2007 when Hamas fighters seized the enclave.

"This has to be done gradually," said Ilan Mizrahi, former head of Israel's National Security Council and now a defense analyst. "The more we witness them improving and arresting radical elements, the more authority we will give them."

Other Israelis, however, oppose turning over authority to Palestinians, noting that during the 2000 intifada, or uprising, Palestinian troops who had been given control over parts of the West Bank turned their guns against Israeli soldiers.

"It's only a matter of time until they take the techniques and teaching that we are giving them now, and that the U.S. is paying for, and use them against us," conservative Israeli lawmaker Danny Danon said. "History has taught us."

Most agree that today's Palestinian forces are better trained than the forces a decade ago, when rampant corruption within the authority meant many unpaid police officers resorted to crime.

After Palestinian Authority troops were chased out of Gaza nearly three years ago, the United States and European Union started investing in reform. Lt. Gen. Keith Dayton arrived to serve as the U.S. security coordinator for Israel and the Palestinian Authority. The U.S. has spent $186 million in training and infrastructure so far, with $100 million more budgeted for this year.

But Ali, who spent years in Lebanon fighting against Israel with the Palestine Liberation Organization, warned that the longer it takes for Israel to return full security autonomy to Palestinians, the more credibility his forces lose.

"It really embarrasses us," he said.

He rejects Israelis' claims that his troops cannot maintain order without them. "This is an excuse because they want to stay in the West Bank," he said.

During a recent trip to a U.S.-built training base in the hills above Jericho, Ali demonstrated his troops' abilities. As some soldiers operated a mock checkpoint, teams of commandos hunted one another through a maze of buildings.

A closer look revealed that several of the trainees carried cardboard cutouts of rifles rather than the real thing. "Not even half of us have guns," said Maj. Samir Abdul Haq, an officer at the training camp.

Ali said Israeli coordination and consultation with the Palestinian forces is also weak. Sometimes his troops receive only a 15-minute warning of impending Israeli operations to enter Palestinian cities or arrest Palestinians.

In December, Ali said, his investigators identified three suspects in the shooting death of an Israeli settler and shared the information with Israelis. An hour before Palestinian forces planned to arrest the men, Israeli soldiers raided their homes and shot all three to death.

"They killed them just to embarrass us," Ali said.

Israelis defended the operation, saying the suspects resisted arrest. "The first mission of our forces is to foil attacks in Israel," defense analyst Mizrahi said. "If we think it would be better to do that by ourselves, that's what we are going to do."

The lack of direct peace talks, which broke down more than a year ago, is fueling the mistrust, said Robert Pastor, professor of international relations at American University in Washington.

Though he criticized Israel for sometimes "undermining and humiliating" Palestinian forces, he acknowledged that they need more work. "They're not there yet," he said.

Some Palestinians concur, saying the security forces still abuse their authority by harassing or arresting political enemies, particularly those allied with Hamas or other rival Palestinian groups.

Journalist Khalid Amayreh, an outspoken critic of the Palestinian Authority, was arrested by Palestinian forces a year ago and held for several days. They told him that he was suspected of supporting terrorism, but he believes the arrest was because of articles he'd written about financial fraud in the authority.

"They are a police state without the state," Amayreh said, and the authority needs to develop stronger courts and other institutions before giving security forces more power. "They need to be more answerable to their own people."