Former drone pilots and instructors have spoken out about their experiences in a new documentary, "Drone".

A new documentary looks at the impact of drone warfare

A new documentary looks at the impact of drone warfare

The film, directed by Tonje Hessen Schei, focuses on the United States military's drone program, exposing the number of civilians killed by drone operators and the resulting psychological toll on those soldiers controlling the deadly machines.

Speaking at a press conference on Thursday, former drone instructor Michael Haas said that many soldiers resort to alcohol and drugs, such as bath salts and synthetic marijuana, to help them cope with the stress and trauma of their jobs.

"Ever step on ants and never give it another thought? That's what you are made to think of the targets - as just black blobs on a screen," Haas told The Guardian. "You had to kill part of your conscience to keep doing your job every day - and ignore those voices telling you this wasn't right."

Brandon Bryant, another former drone operator, added that drone strikes are exacerbating the problem of terrorism: "If you kill someone's father, uncle or brother who had nothing to do with anything, their families are going to want revenge."

According to multiple international organisations, American drone strikes in Pakistan, Afghanistan and other nations have killed hundreds of civilians. The documentary promises to reveal "intimate stories from the war on terror", and hopes to spark a conversation about the future of the US military.

"The drone program has large support here in the States, and we believe that is due to lack of information," said documentary director Schei. "We hope to change this."

"Drone" premiers in the USA and Canada on Friday November 20th.