Since he joined Afghanistan's police force in 2001, he has been mistakenly bombed by a U.S. airplane that killed seven of his colleagues. He has paid bribes to government officials, he says, and taken bribes to balance his books. He recalls watching a friend buy a police job for $2,000, and notes that posts with better opportunities for bribery are available for upward of $10,000.

Corruption has made it easier for the Taliban to infiltrate police ranks and carry out lethal attacks, according to Najib.

"The president is crying, but nothing has changed," says Najib, who still walks with a limp from the U.S. bombing. "People are unhappy, and more and more it will become difficult for the Americans and good for the Taliban. These people (U.S. troops) are not making one mistake, but they are making one thousand mistakes and they are killing many people."

In an exclusive interview with the AP, President Hamid Karzai said the mistakes of troops are seriously undermining his government. But he also spoke candidly about what he described as his failure and gave a frank assessment of his track record, as he prepares to run for re-election next year. He said he had achieved some but not all of his goals for Afghanistan.

"Afghanistan does not have a properly functioning government yet," he said. "With regard to corruption, it's a deeper problem, it's an Afghan problem. It's the problem of an inefficient government machinery. ... It's a problem of so much money coming into Afghanistan, it's a problem of the international presence."

It is now so dangerous outside the capital that Afghans are afraid to travel hundreds of miles of newly-paved roads, and most international aid groups have forbidden their staff to do so altogether. Truck drivers who have no choice often say thieves and thieving police are a bigger worry than the Taliban.

"An Afghan trucker put it succinctly: 'Forget the Taliban, our biggest problems are with the police,"' says Seth Jones, an analyst with the U.S.-based RAND Corporation and author of a report on the rise of Afghanistan's insurgency.

Afghan Interior Ministry spokesman Zemeri Bashery puts the corruption level at barely 20 percent of the force, and says efforts are being made to tackle it. But many Afghans think otherwise.

Kidnappings in Kabul are in the double digits this year, according to the attorney general's office, and Afghans suspect police involvement. Most are for ransom rather than because of politics.

In the meantime, the Taliban is advancing.

Moiabullah, a black-bearded Taliban from the troubled province of Ghazni, fled to Iran after the Taliban collapsed in 2001 but returned several months ago.

"People are fed up with this government," he says. "No one is working honestly. If you provide a good life, factory or jobs, of course no one will follow Mullah Omar (the Taliban leader)."

Out at the heavily fortified, sprawling U.S. military base at Bagram, north of Kabul, Brig. Gen. Mark Milley says the Taliban and al-Qaida are enemy number one, and corruption is enemy number two. But he claims the troops are inching forward in bringing security to the country.

"The western forces, international forces, Americans in particular are the most disciplined in our use of deadly force," says Milley, the deputy commanding general of operations. "We think we are succeeding."

Back at the tribal council, or shura, in Nangarhar, the eldest of the elders disagrees.

"It is a shame for them," says Abdul Samad, a tall, lanky man in his seventies with a silver beard on his gaunt face. "It was a good opportunity after the Taliban. But it is gone."