DUBARDAN, Iraq — Smoking cigarettes in a tent with a dirt floor just outside an isolated village in northern Iraq, the police officers recalled the heady days working alongside American forces and launching dozens of operations to kill and capture Qaeda militants in Mosul, Iraq’s second-largest city.

The Americans are long gone, Al Qaeda in Mesopotamia has morphed into the Islamic State and the Iraqi government has not paid their salaries in months, leaving the officers grappling with their fate in a cold tent in what is supposed to be a training camp.

“We are in a camp like refugees, without work or salaries,” said Seif Ahmed, a SWAT team member wearing a “U.S. Army” T-shirt. “ISIS is our target, but what are we supposed to fight it with?”

As the United States dispatches military advisers to help Iraq build a force to fight the Islamic State, often referred to as ISIS, the police of Nineveh Province, who have experience and self-interest in actually battling the jihadists, have been largely abandoned. In a region that the Islamic State now controls, lingering distrust by the Shiite-led central government has stymied efforts by provincial officials to turn the former police into a local force. The central government fears that the police officers, who are mostly Sunni, will sell their weapons to the jihadists — or join them.