The Tomorrow War (2021)
etim 2 points 3 years ago*. (Contains Spoilers)

The ppl in the past were already gearing up manufacturing, research, breeding, etc. ever since the 1st time soldiers appeared to them on the soccer field, gave ‘em the warning AND a bunch of future tech.

They were able to check every draftee’s future to see what wd happen if they stayed. Heavy breeders likely got deferments. The ones sent to the future were all past their peak reproductive ages so better they go off to fight than get in the younger breeders’ way.

The ppl from the future were already severely shorthanded by when the time machine was built. Soldiers from the future were better used to fight rather than breed (besides, they were already the product of the past’s breeding programs—and inbreeding wd be a danger).

The younger men living in the past wd be more than happy and willing to fulfill their patriotic duties of increased breeding. No more monogamy, bang like bunnies? Sign me up, sir!

A butterfly effect? They were trying for a butterfly effect to change a future that o/wise was total annihilation.

Abyss 4 points 3 years ago.

Besides the first sentence, everything else you said is just assumptions and never explained in movie. You do realize that the moment they went to past that they created an alternate timeline, so the future they were being sent to fight technically wasn’t there own. The aliens would still attack them in future and they would have to do this over again if the timeline is linear like they portrayed here. It only would make sense if they just prepared the past instead of risking lives of people from the past which would alter their future worse.