Tom Cruise was at one point interested in the project, but was never officially attached to it. Director Noyce wanted Heath Ledger to play the role that went to Brendan Fraser, but was very happy with Fraser's work in the film.
The film ends with newspaper stories written by Thomas Fowler about Vietnam from 1954 to 1966. However the book on which the film was based was published in 1955, so these are mostly events which happened after the book came out.
Miramax had paid $5.5 million for the rights to distribute the movie in North America and some other territories, but then shelved it for a long time. Miramax even planned to send this movie to go straight-to-video. But Michael Caine successfully persuaded Miramax to screen this movie at 2002 Toronto International Film Festival. This movie received many good reviews at the Film Festival, so Miramax decided to release this movie in the United States theatrically.
At a Q&A in Dublin in 2003, Philip Nonce said that Paramount originally planned to finance the film, and at one point Sean Connery and Johnny Depp were to play the lead roles. Paramount eventually passed on the film.