SAN DIEGO -- President Barack Obama has assured Americans he opposes sending U.S. ground troops to crush Islamic extremists in Iraq and Syria -- well aware the country is not ready to return to the battlefield with its war wounded still recovering from a decade of conflict.
While drone operators are not physically in harm's way -- they do their work at computer terminals in darkened rooms far from the actual battlefield -- growing research is finding they too can suffer some of the emotional strains of war that ground forces face.
"It can be as impactful for these guys as someone in a foxhole," said Air Force spokesman Tom Kimball.
In a rare partnership, U.S. and Arab allies last week launched a military air assault against Islamic State strongholds in Syria. Americans have also been conducting airstrikes in Iraq since August. Both assaults have incorporated the use of unmanned aircraft, according to Air Force officials.
Administration officials said the U.S. on its own also bombed targets of an al-Qaida cell in Syria because intelligence showed that the Khorasan Group was in the final stages of plotting attacks against the U.S. and Europe.
The broadened campaign includes a dozen teams of U.S. military advisers embedding with Iraqi commanders in the field at the brigade level or above, and at least 125 U.S. military personnel flying and maintaining Iraq-based U.S. surveillance aircraft to collect targeting information for Iraqi troops.
Drone operations in recent wars
The Bush and Obama administrations have both used the 2001 authorization of force against al-Qaida to justify drone strikes against terror targets in Pakistan, Yemen and Somalia.
During the wars in Iraq and Afghanistan, drone operators pulled long shifts at U.S. bases, watching full-motion video across multiple screens. Some would follow the daily life of locals for months to assess threats before an airstrike was ordered.
Then they might analyze the carnage and damage from bombings before driving home to eat dinner with their families and maybe play soccer with their children -- a jarring shift that may contribute to stress, mental health experts say.
Trauma from watching bloodshed
Brandon Bryant manned the cameras for pilots at Air Force bases in Nevada and New Mexico for about five years.
He said he still suffers from insomnia, depression and nightmares three years after he participated in his last mission. He witnessed the direct killing of 13 people, and his squadron was credited with killing 1,626 enemies.
"I would go to sleep and dream about work, the mission, and continuously see the people I'd watched on the screen earlier now in my own head repeatedly being killed," he said, adding that he felt alone and that no one wanted to talk about it.
Bryant, 28, said he has been diagnosed with post-traumatic stress disorder by the Department of Veterans Affairs.
He said the military's drone community has shunned him for speaking out.
What is known
In the first study of its kind, the Armed Forces Health Surveillance Center found the amount of behavioral issues, such as anxiety, depression and PTSD, affecting drone pilots was comparable to that of traditional pilots.
Researchers analyzed the health records of 709 drone pilots and 5,256 traditional pilots from 2003 to 2011. The study was published last year. The study's author Dr. Jean L. Otto said the message was that "just because service members are not physically deployed to a war zone doesn't mean there is less of a mental health risk."
Watching explosions, which sometimes include civilian casualties, may produce "moral injuries" -- a psychological wound from witnessing something that goes against a person's beliefs or moral code that is gaining recognition by the military.
"Pilots of manned aircraft come in, drop bombs and go back and someone else does the damage assessment," said Nancy Cooke, an Arizona State University professor who looks at technology's impact on psychology.
"Drone operators actually see the results of what they've done," she said. "So when people say this is just a video game, nothing could be further from the truth for them. They see the body parts."
And operators have few chances to talk about their experience because they are limited for security reasons.
How is military responding?
Last year, the Air Force started assigning chaplains and psychologists to its drone units. Leaders have tried to improve shifts to ease fatigue, while doctors are developing ways to treat moral injury, which also affects those on the battlefield.
Army Lt. Col. Douglas Pryer, who has written about moral injury, said in an email that as warfare becomes increasingly remote-controlled, the risk of psychological wounds among drone operators will grow.
Technological advances mean operators soon may see the faces of their targets and that could put them at as much risk for moral injury as infantrymen "fighting in hand-to-hand combat and seeing up close and personal the agony of those they killed," he said.
"Americans tend to see drones as a means toward an ideal -- harming the enemy without being harmed," he said. "This ideal is actually impossible to achieve."