Having those sent to fight in a war being the ones to decide if the war should be fought was on of the major points in General Butler’s 1935 book War is a Racket
My proposed alternative would be, when you sign up for the military, you are presented with a list of "regions" in which you are willing to be deployed in a combat role, with pay/benefits scaling accordingly the more regions (and more "in demand" regions) you are willing to be deployed. So you could potentially ahve a group that would not fight in the Middle East but would fight in the Pacific, etc. Of course you can't have too many declining service in too many reasons, but if it starts to get expensive to find recruits willing to fight in a given region thats a clear sign somethings amiss with popular sentiment.
https://en.wikipedia.org/wiki/Business_Plot
> Butler, a retired Marine Corps major general, testified under oath that wealthy businessmen were plotting to create a fascist veterans' organization with him as its leader and use it in a coup d'état to overthrow Roosevelt.