I highly enjoyed this movie. Dunst has never been better, and all of the cast shined. And yeah, that short scene with Plemons was sinister as bloody hell. I enjoyed the whole atmosphere, the sound effects and the whole cinematography.
I totally see the the likeness of Apocalypse Now, and the Conrad novel which it was built on, since this travel really feels like going to the "heart of darkness", in order to get the President's comments on this war.
The critisism that this is somehow apolitical, especially in times like this is a critique I've read way before watching the movie. As a Scandinavian/non American I totally understand that POV, and how that would've been a missing point. However, for me it was completely clear that this US President would be totally unwanted by most democratic Western countries. Kinda like during 2016- and up till now.. (I want him in jail, even though it wont happen lol). Hence the more subtle "not-on-the-nose" angle suited me fine.
I have a slight nitpick:
It seemed like all of a sudden the President's army had suddenly fallen. Maybe it's just me, but it felt like: Yahooo, we're going to invade the White House now!
IMHO the strength of this movie is what happens to humans, and how they tend to behave in a truly severe potential catastrophy (a civil war is the worse case scenario ever). And Garland delieverd that in spades IMHO.
The money shot photograph the young girl managed to take in the end, in which we see the proud soldiers smiling around a couple of corps tells it alls IMHO.