Former drone operator Brandon Bryant tells NBC's Richard Engel that he felt like he became a "heartless" "sociopath" under the drone program.

A former Air Force drone operator who says he participated in missions that killed more than 1,600 people remembers watching one of the first victims bleed to death.

Brandon Bryant says he was sitting in a chair at a Nevada Air Force base operating the camera when his team fired two missiles from their drone at three men walking down a road halfway around the world in Afghanistan. The missiles hit all three targets, and Bryant says he could see the aftermath on his computer screen – including thermal images of a growing puddle of hot blood.

“The guy that was running forward, he’s missing his right leg,” he recalled. “And I watch this guy bleed out and, I mean, the blood is hot.” As the man died his body grew cold, said Bryant, and his thermal image changed until he became the same color as the ground.

“I can see every little pixel,” said Bryant, who has been diagnosed with post-traumatic stress disorder, “if I just close my eyes.”

Bryant, now 27, served as a drone sensor operator from 2006 to 2011, at bases in Nevada, New Mexico and in Iraq, guiding unmanned drones over Iraq and Afghanistan. Though he didn't fire missiles himself he took part in missions that he was told led to the deaths of an estimated 1,626 individuals.

In an interview with NBC News, he provided a rare first-person glimpse into what it’s like to control the controversial machines that have become central to the U.S. effort to kill terrorists.

He says that as an operator he was troubled by the physical disconnect between his daily routine and the violence and power of the faraway drones. “You don't feel the aircraft turn,” he said. “You don't feel the hum of the engine. You hear the hum of the computers, but that's definitely not the same thing.”

At the same time, the images coming back from the drones were very real and very graphic.

“People say that drone strikes are like mortar attacks,” Bryant said. “Well, artillery doesn't see this. Artillery doesn't see the results of their actions. It's really more intimate for us, because we see everything.”

A self-described “naïve” kid from a small Montana town, Bryant joined the Air Force in 2005 at age 19. After he scored well on tests, he said a recruiter told him that as a drone operator he would be like the smart guys in the control room in a James Bond movie, the ones who feed the agent the information he needs to complete his mission.

He trained for three and a half months before participating in his first drone mission. Bryant operated the drone’s cameras from his perch at Nellis Air Force base in Nevada as the drone rose into the air just north of Baghdad.

Bryant and the rest of his team were supposed to use their drone to provide support and protection to patrolling U.S. troops. But he recalls watching helplessly as insurgents buried an IED in a road and a U.S. Humvee drove over it.

“We had no way to warn the troops,” he said. He later learned that three soldiers died.

And once he had taken part in a kill, any remaining illusions about James Bond disappeared. “Like, this isn’t a videogame,” he said. “This isn’t some sort of fantasy. This is war. People die.”

Courtesy Brandon Bryant Brandon Bryant stands with a Predator drone in Nevada. He says that as an operator he was troubled by the physical disconnect between his daily routine and the violence and power of the faraway drones.

Bryant said that most of the time he was an operator, he and his team and his commanding officers made a concerted effort to avoid civilian casualties.

But he began to wonder who the enemy targets on the ground were, and whether they really posed a threat. He’s still not certain whether the three men in Afghanistan were really Taliban insurgents or just men with guns in a country where many people carry guns. The men were five miles from American forces arguing with each other when the first missile hit them.

“They (didn’t) seem to be in a hurry,” he recalled. “They (were) just doing their thing. ... They were probably carrying rifles, but I wasn't convinced that they were bad guys.“ But as a 21-year-old airman, said Bryant, he didn’t think he had the standing to ask questions.

He also remembers being convinced that he had seen a child scurry onto his screen during one mission just before a missile struck, despite assurances from others that the figure he’d seen was really a dog.

After participating in hundreds of missions over the years, Bryant said he “lost respect for life” and began to feel like a sociopath. He remembers coming into work in 2010, seeing pictures of targeted individuals on the wall – Anwar al-Awlaki and other al Qaeda and Taliban leaders -- and musing, “Which one of these f_____s is going to die today?”

In 2011, as Bryant’s career as a drone operator neared its end, he said his commander presented him with what amounted to a scorecard. It showed that he had participated in missions that contributed to the deaths of 1,626 people.

“I would’ve been happy if they never even showed me the piece of paper,” he said. “I've seen American soldiers die, innocent people die, and insurgents die. And it's not pretty. It's not something that I want to have -- this diploma.”

Now that he’s out of the Air Force and back home in Montana, Bryant said he doesn’t want to think about how many people on that list might’ve been innocent: “It’s too heartbreaking.”

The Veterans Administration diagnosed him with Post-traumatic Stress Disorder, for which he has undergone counseling. He says his PTSD has manifested itself as anger, sleeplessness and blackout drinking.

“I don’t feel like I can really interact with that average, everyday person,” he said. “I get too frustrated, because A) they don't realize what's going on over there. And B) they don't care.”

He’s also reluctant to tell the people in his personal life what he was doing for five years. When he told a woman he was seeing that he’d been a drone operator, and contributed to the deaths of a large number of people, she cut him off. “She looked at me like I was a monster,” he said. “And she never wanted to touch me again.”

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