>>17856565>The Roman military used to be about citizens fulfilling civic duty through military serviceThe Roman army wasn't filled by civic duty. It was filled by widespread mass conscription. You didn't get a choice in the matter. It was during the reign of Augustus that this system ended to a volunteer army which is how it remained.
>and about Roman allies fighting in exchange for the privileges of limited citizenshipThe important Roman allies in Italy also all practiced mass conscription. For nearly 200 years they fought essentially with no citizenship benefits even in limited capacity. They fought because they gained wealth, continued practices in their society which they shared with the Romans and actively desired to fight.
>people no longer had any obligation or real reason to serve in the Roman military if they had citizenship alreadyThe size of the Roman army increased massively even after citizenship was granted to everybody. During the reign of Diocletian and Constantine the size of the army skyrocketed to almost double what it once was.
>So the Roman military became increasingly dependent on a new class of soldier: the foederatiThe Foederati weren't part of the Roman army, that's like the entire point. The Roman army itself was still largely local and formed by volunteers and conscripts. It's estimated only some 20% of the actual army in the West were settled foreigners, who were not Foederati.
>>17856579>Look at what happened with the Valens regime and the GothsThe Goths were completely independent from Roman power while the Gauls were not. The only difference between the two was the Gauls were crushed militarily and the Goths were not.
>Many Gallic tribes were like the Goths; defeated by a non-Roman entity and driven into Romeโs armsMost Gauls were defeated by Caesar, and earlier in the Middle Republic after decades of constant warfare. They didn't accommodate with Rome because they wanted to, they were forced into the relationship by defeat