Christopher Nolan’s awareness of J. Robert Oppenheimer stems all the way back to his youth, per his interview with This Playlist. There, he admits that hearing the song “Russians” by Sting made him aware of the Cold War and Oppenheimer’s impact on nuclear relations between world powers. “[Sting] Referenced Oppenheimer’s Deadly Toy. Nolan quoted Sting lyrics in the song. “It really affected me, like so many others with fear of nuclear Armageddon,” Nolan stated.
Nolan says that he does not imagine any particular actor when he is typing each line. Nolan said that he tries to write without actors in mind. “If you are writing with an actor or a performance in mind you will never challenge them”, he explained.
He knew exactly who to contact by the time his script was finished. When we were finished, I saw the copy of “American Prometheus” that had been on my desk for many months. It was a face with intense blue eyes looking upwards. You look up at the copy and think “I know someone who could do that.” I know who can be that person,'” he said.
Cillian Murphey was his first choice. And his performance — among many other things — will stun audiences watching “Oppenheimer” when it opens on July 21.