[Allied] got the attention of (director) Bob Zemeckis and Marion Cotillard. I'm glad I waited. If it had been made 15 years before, who knows how it would have looked, but it's got the best possible cast, director and everything. It's been fantastic. It was worth waiting.

Obviously, television is a writer's medium, so you get a lot more power and authority. With a film, the discipline is having a beginning, middle and end, and having it work in a specific space of time.

The time came where I was able to write an original screenplay [Allied], and it would be read and noticed. I had a meeting with Brad [Pitt], just around the time that he was making World War Z. I basically told him the story and said, "This is what I want to do," and he really responded, so that helped me put the thing together and write it.

I wanted to take a damaged individual in a damaged society with damaged relationships between nations and take a look at how this individual survives amongst them, and that for me as a writer is the connection that you needed to get inside the skin of the main character and wonder how he's going to cope with all this.

I was 21, when I heard the story that inspired this [thriller Allied], and I wasn't even a screenwriter then.

True stories are always good because they're so odd, and so unlikely.

Sometimes if you're a director, you want to believe that you're great and capable at all aspects - the technical side, the lights, everything - but I'm not.