In February 2024, it was announced that A24 was developing a war film with Ray Mendoza and Alex Garland set attached, which would follow Garland's film Civil War, for which Mendoza was the military supervisor. The duo wrote the script and planned to direct the film together. At the time of the announcement, Charles Melton was in negotiations to star in the film.[2]Joseph Quinn was being considered for the cast as well.[3]D'Pharaoh Woon-A-Tai was cast in the film to portray Mendoza himself in March 2024, when the title was confirmed to be Warfare,[4] with Kit Connor, Cosmo Jarvis, Will Poulter, and Finn Bennett being added to the cast as well.[5] That same month, Garland announced his intentions to step back from directing films and focus on writing, while announcing that his directional role in Warfare would be more of a supporting role to Mendoza's.[6] In April 2024, Noah Centineo, Taylor John Smith, Adain Bradley, Michael Gandolfini, Henry Zaga, and Evan Holtzman joined the cast.[7]