I'm guessing they are learning to use and maintain US-produced equipment we've sold them. Have they ever been trained or mobilized to keep order in the US?Oh hell, we have them all over the place.
There are contingents of Germans stationed at both Fort Bliss and Fort Sill for training German Air Defense forces. These units have been on those two bases for at least 50 years, possibly since the Bundeswehr was first constituted after WWII.
In fact, it was always amusing when we would have a major Change of Command ceremony there, and the German Contingent would be a part of it. And on the day of the ceremony after a week of practice the Clergy for the German Air Force would be there in his formal "Friar Tuck" outfit. In actual black cowl and robes, with a white rope belt and wood cross on twine around his neck. They had their own school on the base for their children, their own chapel, and there was always a large selection of foods from Germany at the commissary.
There are also permanently based personnel from the UK, Italy, Germany, and others at Holloman Air Force Base. When I was at the Mare Island Naval Shipyard we had permanent groups from both Taiwan and Japan there.