Comment by inglor_cz
11 days ago
Both the Romans and the US had success with immigrants in the military, provided that they were thoroughly mixed. A unit with 35 ethnicities in it usually does not rebel "like one man".
The Roman way started to fail when they moved to the foederati model, where there would be units of, say, only Goths under a Gothic commander. That proved dangerous.
Did either work for Kakania/Austria-Hungary?
The Hapsburg empire, in its various incarnations, existed for almost four hundred years (1526-1918), and most of the time, their troops were loyal, so the answer is yes?
But one has to be careful: while their military was diverse, it wasn't really made of immigrants. It was simply built out of very diverse local ethnicities that were settled in the same place for centuries. Which means, for example, that when the Kaiser fought against the Turks, everyone involved regardless of language had an incentive to fight, because their own homes and freedom were at stake.