Justin Theroux is best known in the film industry as an actor, with roles in a variety of movies such as American Psycho, Mullholland Drive, and Zoolander, but Theroux is also a screenwriter, having worked as such in Rock of Ages, Tropic Thunder, and Iron Man 2. His experience in the Marvel Universe as writer was brief, but he was integral to setting up the MCU and, eventually, The Avengers. Team-ups are now a go-to formula in the superhero genre, but before Marvel took that big step, Theroux was unsure about its outcome.

While promoting Zoolander 2, Theroux spoke to Italian outlet Bad Taste about his time working with Marvel Studios, sharing that he was skeptical about the idea of a film wherein Iron Man and the rest of his teammates were together on the big screen.

Theroux shared the following, as translated by Comicbook.com:

"I remember at that time talking about The Avengers with Kevin [Feige]. I remember that I told him, 'I don't know if this is going to work, having Iron Man and all these characters together'. But then he ended up doing something really special."

Iron Man 2 vs Whiplash

Joss Whedon's The Avengers went on to become one of the highest grossing films of all time and helped set the standard for massive cinematic universes based on comic books as we know them. It's fair to say that without The Avengers there wouldn't have been a Phase 2 and Phase 3 of the Marvel Cinematic Universe. While The Avengers started a new era in the film industry, and Marvel has since released various big hits, not every product from the MCU has been well received.

Iron Man 2 received mixed reviews and was heavily compared to its predecessor. Theroux reflected on this matter, stating that, although it has its flaws, he is proud of his work:

"You know, as happens very often, it is not easy to live up to expectations. And after the first Iron Man, those for the sequel were extremely high. [You] go to see [the film] with a wealth of expectations... and the film had a release date even before we started working on it so we had to work fast. And I will not complain about anything or anyone, mind you... It was a team effort and I really love people like Jon Favreau and Robert Downey Jr. We tried to please the fans and to give shape to something spectacular... But sometimes things end up not going in the right direction, although there are parts of the movie that I'm really proud [of]."

Ivan Vanko Iron Man 2 Whiplash

Theroux hasn't worked with Marvel Studios again after Iron Man 2, but has instead worked in other productions as writer, producer, creative consultant, and, of course, actor. He is currently working on the adaptation of Paula Hawkins' novel The Girl on the Train, directed by Tate Taylor, as well as being the lead character in the drama series The Leftovers.

Whether you're a fan of Iron Man 2 or not, there's no denying its importance in helping create the larger MCU.

Captain America: Civil War will release on May 6, 2016, followed by Doctor Strange – November 4, 2016; Guardians of the Galaxy 2 – May 5, 2017; Spider-Man – July 7, 2017; Thor: Ragnarok – November 3, 2017; Black Panther – February 16, 2018; The Avengers: Infinity War Part 1 – May 4, 2018; Ant-Man and the Wasp – July 6, 2018; Captain Marvel – March 8, 2019; The Avengers: Infinity War Part 2 – May 3, 2019; Inhumans – July 12, 2019; and as-yet untitled Marvel movies on May 1, July 10 and November 6, 2020.

Sources: Bad Taste (via Collider and Comicbook.com)