Throughout history, empires end once the domestic military aged males refuse to fight
When those capable of killing do not believe in the reasons to risk being killed.
And the western empire has absolutely decimated the common male with feminism.
The western man will not fight for a society that sees women above him and for women who see themselves as too good for his children.
So the bet is on drones and machines.
The empire does not need humans enmasse.
Only a few ultra skilled ones.
Once complete, public support and consensus becomes less important for a war than ever before.
Expect perma resource wars.
Perma destruction and endless attempts at acquisition.
There is a close future where drones and machines from different empires fight endlessly largely ignored by the populace.
Very much like the ongoing cyber attacks between nation states which happen now.
We are in a permanent cyber war and nobody cares or talks about it.
Soon that war goes hot and stays hot.
Brown people die.