To play Strauss, Christopher Nolan and Emma Thomas approached an actor they had wanted to work with for many years, two-time Oscar® nominee and longtime Iron Man, Robert Downey, Jr.

The Oppenheimer opportunity arrived in Downey Jr.’s life at a moment when he was trying to be choosy following his blockbuster run playing the foremost avenger of the Marvel Cinematic Universe. “I had been cooling my heels for about a year before the pandemic, just reacquainting myself with my family and other interests because I had been working super consistently,” says Downey Jr., who recently produced “Sr.”, the acclaimed documentary about his late father, the revered experimental filmmaker Robert Downey, Sr., and their relationship. “But this was Christopher Nolan, doing something that was important to him. The cast was this large gathering of folks who have their choice of projects. And just as soon as we were under way, world events lined up in a way that turned this movie into an important metaphor that could speak to any number of things. So, it was kind of a no- brainer.”