Harry Styles (Dunkirk) Dunkirk

Harry Styles plays Alex, a Highlander soldier who joins Tommy and Gibson on the grounded trawler. Alex is suspicious, hostile, and frightened — the character most likely to turn on the group under pressure. It was Styles's film debut, and Christopher Nolan has said he was unaware of Styles's fame as a musician when he cast him.

Nolan cast him from an open call of thousands

Styles beat out thousands of candidates in the same open-call process that yielded Fionn Whitehead. Nolan auditioned the young men in rotating combinations, looking for chemistry and the right period feel.

Nolan told The Hollywood Reporter that he was not aware how famous Styles was: "I don't think I was that aware of how famous Harry was. I mean, my daughter had talked about him, but I wasn't really that aware of it. So the truth is, I cast him because he fit the part wonderfully and he was a compelling actor for the role."

Nolan also noted that Styles had "an old-fashioned face" — "the kind of face that makes you believe he could have been alive in that period." (hollywoodreporter)

Alex carries the trawler sequence's moral crisis

In the grounded trawler, as German soldiers shoot through the hull and water floods in, Alex proposes shedding weight — someone must leave so the rest can survive. He volunteers Gibson, the silent soldier who has never spoken, accusing him of being a German spy. When Gibson speaks French, Alex turns the accusation into nationalist contempt: "A frog. A bloody frog. A cowardly little queue-jumping frog." The Highlanders side with Alex.

Alex's hostility is not villainy but panic — the same survival instinct that Tommy channels through cunning, Alex channels through scapegoating. The character registers because Styles plays fear as aggression without overplaying either.

Nolan praised the performance: "I think what he does is extremely subtle because it's very real." (billboard)

The casting generated more press coverage than any other element

The announcement that a One Direction member had been cast in a Christopher Nolan war film generated enormous media attention — more than any other casting decision. Nolan was careful not to "oversell" the role, emphasizing that Styles had earned it through the same process as every other young actor. The fear was that his celebrity would distract from the film's ensemble approach; the result was that Styles's performance was judged on its own merits and reviewed positively by most critics. (billboard)

Dunkirk launched Styles's acting career. He went on to star in Don't Worry Darling (2022) and My Policeman (2022).