...my brother and I noticed that there were never any "good" Germans (there were "Nazis" in TOS, Voyager, and Enterprise) in any version of Star Trek. Between the movies and TV they have shown Arabs, Indians, Native Americans, Brits, Irish, Scots, French, etc. Never anyone with a German accent or even a German name. Apparently there are no Germans in the 23-24th centuries.
Karl Jaeger was a meteorologist who served in the science department aboard the USS Enterprise during James T. Kirk's five-year mission. He had German ancestors. Upon hearing Karl Jaeger's German name in 2267, Trelane asked him in German if he were a German soldier and reenacted part of a German marching song. (TOS: "The Squire of Gothos")
Kurt Mandl was a senior member of the Federation's Terraform Command during the mid-24th century who was assigned as director of the terraforming mission, coordinated from the Velara Base, on the planet Velara III. (TNG: "Home Soil") According to the shooting script, Kurt Mandl was intended to be of German descent; he was played by the German actor Walter Gotell.