Garland's decision to leave the politics of this war obscure is both commercially and politically shrewd, and highly effective. It means that American viewers of Right, Centre or Left conviction, or none at all, can watch it as an antiwar film whose horrifying events could as well be happening in the Ukraine or Gaza. It also subverts our own class stereotypes outside of the USA -- are those violent characters who look like Jan 6th Trump supporters on the East or the West side? Once the soldiers take charge, politics evaporate.
Garland has announced that he's retiring from directing after this movie, which is a pity since for me he's filled a movie space that Spielberg vacated due to increasing sentimentality. Garland's 'Ex Machina' is the most caustic depiction of AI and Silicon Valley megalomania I've seen, and was made several years before anyone had even heard of GPT. His 'Annihilation' is just plain nuts, but it's the most unsettling 'horror' film I've seen, and I don't even like horror films.