Brandon Bryant, from Missoula, Montana, spent six years in the US Air Force operating Predator drones from inside a dark container 7,000 miles from the conflict.
The 34-year-old fired missiles remotely from a base in Las Vegas, Nevada. He also spent time at drone control centers in New Mexico and Iraq.
But after following orders to attack an enemy position in Afghanistan that led to the death of a child, he knew he could not keep going and quit the military to speak out against the US drone program.
As a 'sensor' Bryant controlled multiple camera systems and was responsible for training the deadly weapons on their target while a pilot directed navigation.
Staff Sergeant Bryant said he suffered post-traumatic stress disorder after his time aiming the Hellfire missiles at people on the other side of the world.
He signed up to the Air Force when he was 19 and made his first kill in 2007. From 2006 to 2011 his squadron hit 1,626 targets, including women and children.
To Bryant's knowledge, he killed 13 people, according to The Sun.
After aiming a Predator drone at three men on a dirt road in Afghanistan, Bryant watched the aftermath unfold on a monitor.
He told how when he registered this first kill his colleague celebrated by shouting 'splash'.
But the horror of the bombing still lives with him as he watched blood shoot from his victim before his body turned cold on thermal imaging cameras.
He said: 'I saw the blood squirt out of his leg, then I watched him cool down.
'That image on the screen is still in my head. Whenever I think about it, it still hurts me.
'When I pulled the trigger, I knew that it was wrong. When the missile struck I knew in my soul I had become a murderer.'
One of Bryant's most traumatic experiences came later that same year when he accidentally struck and killed a child in Afghanistan with a direct hit.
He was tasked with taking out an enemy target believed to be inside a building, but at the last minute he saw a small child run into his cross-hairs just as the drone landed.
When he questioned what had happened, his superiors told him it was merely an animal he had killed.
An image analyst who watched the drone video feed at the time of the strike, known as a 'screener', initially tried to tell him it was a dog.
But a colleague sitting next to him agreed it was 'probably' a child and nonchalantly added 'yeah, whatever, probably'.
After reviewing the tape of the incident, Bryant went to his bosses, but was told, 'it's a f*****g dog, just drop it'.
After the horrors of his time as a drone operator Bryant has spoken out against the US military's use of the program, testifying before the United Nations about America's overseas drone operations.
He has also spoken in Germany and told lawmakers about its role in aiding the US operations.
Bryant now denounced the US use of unmanned drones, saying they are 'worse than the Nazis, because we should know better'.
He said: 'We think about the Nuremberg Trials. All these guys that got convicted during the trials, the one thing that convicted them all was, ''well I was just doing my job''.'
In May 2016 Norwegian documentary filmmaker, Tonje Hessen Schei, produced a film featuring Bryant's experiences of how he joined the program, called Drone - This Is No Game!.
Drone pilots Bryant, as well as colleague Michael Haas, were shown as examples of how the CIA recruits video gamers and trains them to kill by remote control.
Upon joining the air force, Bryant said he never wanted to be a drone operator and was ushered into a movie theater and shown clips of drone strikes to the sounds of heavy metal band, Metallica.
Then a sergeant told the new recruits, 'your job is to kill people and break things', and 'tried to make it sound cool'.
When he tried to get out of it, his commander, 'do your f*****g job', Bryant told The Sun.
Other members of the air force mocked drone operators, calling them the 'Chair Force', and his drone squadron jokingly referred to themselves 'stick monkeys', he said.
After leaving the air force, Bryant wanted to become a survival expert but near died when he suffered a fractured skull when a log fell on his head.
Since being such an outspoken critic of the US drone program, Bryant says his family have been threatened.
After he spoke to a German parliamentary inquiry committee in 2015, two American Air Force officers showed up at the house of Bryant's mother in Missoula, Montana.
He said they told her she was on a Daesh (ISIS) 'hit list', which Bryant's attorney called a clear sign of whistleblower intimidation, according to Shadowproof.
During his testimony in Germany, Bryant went on to describe the integral role the US military base in US Ramstein Air Base plays in the American drone program.