Filming has officially begun on Snowden, Oliver Stone’s upcoming biopic on NSA whistleblower Edward Snowden. The film stars Joseph Gordon-Levitt in the title role, with the actor sharing the first image of himself in character via his Facebook account on Tuesday.

The film is based on two biopics of Snowden and the 2013 NSA leak, The Snowden Files: The Inside Story of the World's Most Wanted Man by Luke Harding and Time of the Octopus by Anatoly Kucherena. The script has been adapted by Stone himself, along with writer Kieran Fitzgerald.

Sharing a photo of himself as Snowden dressed in an army uniform, Gordon-Levitt wrote on Facebook, “I was surprised when I first learned this about Snowden--that he enlisted in the US Army in 2004. He wanted to go fight in Iraq, but during basic training at Fort Benning, he broke both of his legs and received an administrative discharge."

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"After that, he was still determined to serve his country (love him or hate him, you gotta admit the guy's strong-willed) and so he ended up getting a job at the CIA, which is where his career in Intelligence began.”

“Today's scenes felt like a really good way to start this shoot. It was hard, but of course, nowhere near as hard as real basic training. And me, I'm just honored and excited to be doing a soldier sequence with Oliver. I keep saying to myself: "fuck, this guy directed Platoon!” the actor continued.

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Snowden also stars Shailene Woodley, Melissa Leo, Nicholas Cage, Zachary Quinto, Tom Wilkinson, Timothy Olyphant, Rhys Ifans and Joely Richardson. The film is scheduled for release in the U.S. on December 25, 2015.

Joesph Gordon-LevittJoseph Gordon-Levitt star in Snowden