It's halfway between a great edge-of-the-seat thriller and a rote story of how WWI was the Bad War. Too much of it felt like it was trying to ape Dunkirk without understanding why it worked. There's a lot of filler dialogue that should be characterisation. There are bits that are bluntly foreshadowed or feel like they should have been but aren't. And because the entire story is fiction, there's little in the way of greater stakes, especially as one character says that just because one attack's been cancelled, that doesn't mean they won't order another in a few days.
The upside is that most of it works as a tense thriller, refusing to downplay the horror - one character accidentally puts his hand through a rotting corpse's chest - and you constantly feel like the characters could die any second. It looks amazing, with Deakins deserving an Oscar for this far more than for the neon porridge of Blade Runner 2049, and the one-shot gimmick actually works very well in context, although there is a cut to black to allow passage of time halfway through. The sound editing is a bit dodgy though, as characters and vehicles keep appearing and disappearing with nary a noise.
It's a first-class thriller, superbly made, but when it tries to say anything it thinks is of value, it stumbles badly.
