Critics say firing weapons from behind a computer screen, while safely sitting thousands of miles away, could desensitize pilots to the act of killing. What separates this, they argue, from a battlefield video game?

But war is rarely so simple, and distance does nothing to numb the emotional impact of taking a life, said Slim (who is referred to here by his Air Force call sign in order to protect his identity).

"People think we're sitting here with joysticks playing a video game, but that's simply not true," Slim, who retired from the Air Force in 2011, told LiveScience. "These are real situations and real-life weapons systems. Once you launch a weapon, you can't hit a replay button to bring people back to life."