Charles Thomas came to dread his morning commute on the Red Mountain Freeway. The Arizona desert resembled the Middle East, and his mind would return to the battlefields of Iraq.

He would clench the wheel of his truck en route to his job at Phoenix's Water Services Department. Someday, he hoped, this feeling would go away. But a year after returning from combat, the 42-year-old still is trying to get his bearings as a security administrative assistant.

Thomas is not alone. Hundreds of National Guard and military Reserve members who have returned after fighting in Iraq and Afghanistan are having a tough time making the mental leap from the battlefield back to the workplace.

Many are in a quiet struggle. They are unable to concentrate, are irritable with co-workers or make mistakes at jobs they once did with ease, according to Veterans Affairs officials and mental health experts.

In more serious situations, the veterans replay the hell of combat. Some drink heavily and use illegal drugs. Others suffer from post-traumatic stress disorder, or PTSD, or have brain injuries.

"You're taken out of a regimen where you're always on your toes, you work seven days a week, and then you're put back as a civilian," said Thomas, an Army National Guard platoon sergeant who led 60 soldiers during a combat tour from February 2005 to March 2006. "There's no transition."

Experts worry that employers have little experience on how to help the estimated one in three veterans who has returned with some sort of readjustment problems.

Once they're back, veterans are "dispersed across all branches of the economy, and you may have one or two at companies," said Phil Potter, a former military psychologist who is an assistant dean at the College of Public Programs at Arizona State University. "Human resources people may not know how to deal with one or two, or they might be less apt to develop programs to help them."

Potter added: "It's not anybody's fault. This is simply a different situation than anything companies have encountered."

Some employers assume their standard benefits are adequate to treat veterans' mental health problems. Others assume veterans are seeking more specific care. That is not always the case.

"A lot of our veterans really think they can deal with (mental health problems) themselves, but it's not going away," said Patricia Tuli, case manager for the Carl T. Hayden VA Medical Center in Phoenix.

"I think there's a tendency not to worry the employers," she said. "These employers have kept these jobs open for them while they were at war. And they're reluctant to take time off work, and they're reluctant to alarm their employers."

Companies that are successfully helping veterans adjust back to civilian life are doing far more than sending care packages overseas. They are educating staff about the role of the National Guard and Reserves and getting to know their employees' commanders. They're revamping personnel policies, forming support groups and ensuring their benefits packages meet veterans' needs.

Thomas thought he could handle returning to work. His military career spans 21 years and includes the first Gulf War and the conflict in Somalia.

"Iraq was definitely the worst," said Thomas, a married father of two who lives in Mesa, Ariz. "The urban warfare was very unpredictable. With Baghdad as crowded as it was, it was a lot easier for someone to blend in with a vehicle bomb."

So during that first week of commuting on Loop 202, he scanned the sandy ground, the dirt blowing across the highway, the tan overpasses and the palm trees. It looked like a highway he used to travel outside Baghdad.

"This is stimulus-driven behavior," said Matthew Friedman, executive director of the National Center for PTSD in White River Junction, Vt.

"In Iraq, you're worried about the roadside bombs. You're driving as fast as you can. You're constantly checking under the bridges and by the side of the road in fear there's going to be some kind of an IED (improvised explosive device) there."

But Thomas is one of the lucky ones. He has the support of family, friends and co-workers who monitor his transition back to civilian life after a year spent fighting in Iraq. Also, his employer, the city of Phoenix, provides additional support for workers who are veterans.

"As best as he can come back into the world and adjust, he's certainly made the effort to do that," said Barbara Cole, a co-worker at the Phoenix Water Services Department.

Thomas' son Daniel, 19, is now in Afghanistan with the Army National Guard. Some of Charles Thomas' advice to his son: