Reply #21: gee, didn't they try something like this prior to the Roman empire's end?

[Lisa]

Back then, the mercenaries were non-Romans ... who eventually turned on their employers.

These days I suppose they could draw from non-Americans ... but also Americans who had served in the actual US military, but were unable to find service or manufacturing jobs once they got home (after everything was outsourced to China and India). This last category would be cost-effective, since the US taxpayer would have already paid for their training ... though one disadvantage would be that they might be unwilling to fire on fellow Americans, if they were used in a "civil disorder" situation.