Germany is a European nation.
After arriving on Earth, the Prysmosian sorcerer Merklynn fabricated a backstory for himself, claiming to be "Garrison Kreiger", the son of immigrants who had fled Germany at the onset of World War I. The war resulted in an anti-German settlement in the United States which would eventually drive Kreiger to enlist in the United States Army shortly before World War II.
Under as of yet undivulged circumstances, the German army came into the possession of several IRON Troopers. The robots donned German Army uniforms and were deployed to Kalistan where they were destroyed by the Screaming Eagles.