The events of Captain America: Civil War irreparably altered the landscape of the Marvel Cinematic Universe. A line was drawn, and The Avengers took sides. However, not every hero in the MCU was involved in the conflict. Benedict Cumberbatch recently addressed Stephen Strange's lack of participation in Civil War, and his response is very much in line with the personality of his character. He explained:
I think he has to be Team Doctor Strange. His job title is 'defender of the fabric of reality.' I mean, he fights other-dimensional threats that are beyond the perception of that very potent squabble. I'd like to think he's going to help them both, rather than take sides.
While speaking with Yahoo Movies about the upcoming release of Doctor Strange, Benedict Cumberbatch addressed the recent conflict between Earth's mightiest heroes during the events of Captain America: Civil War. When asked about the side that Stephen Strange would have picked, he took the diplomatic route and admitted that Strange would fight for his own side. Rationalizing that Doctor Strange operates on a more ethereal plane than the other Marvel heroes, the responsibility would fall upon the Sorcerer Supreme to keep an eye on the big picture, rather than get caught up in the nitty gritty details of a political conflict.
This answer actually shows a fairly deep knowledge of the comic book source material, because Stephen Strange never officially involved himself in the events of Mark Millar's Civil War comic. When the conflict began, Strange admitted that he personally opposed the registration of superheroes, but by the time the fighting began, he had gone into seclusion in the arctic. Rather than take a specific side in the battle, he quarantined himself, and fasted for forty days while meditating on the devastation of the war. If Strange had been introduced to the Marvel Cinematic Universe before the events of the last Captain America film, we can likely assume that he would've done the same on the silver screen.
We will bring you any and all relevant details related to all of the upcoming Marvel Cinematic Universe films as more information becomes available to us. Doctor Strange will conjure a brand new reality for the MCU when it hits theaters on November 4.