KABUL, Afghanistan  The NATO general in charge of training the Afghan police has some tongue-in-cheek career advice for the country’s recruits.

“It’s better to join the Taliban; they pay more money,” said Brig. Gen. Carmelo Burgio, from Italy’s paramilitary Carabinieri force.

That sardonic view reflects a sobering reality. The attempts to build a credible Afghan police force are faltering badly even as officials acknowledge that the force will be a crucial piece of the effort to have Afghans manage their own security so American forces can begin leaving next year.

Though they have revamped the program recently and put it under new leadership, Afghan, NATO and American officials involved in the training effort list a daunting array of challenges, as familiar as they are intractable.