Adam Ant appeared on the front cover of the November 11, 1978 issue of Sounds, and in the three page interview, pages 14-5 & 50, he said this song "caused all the problems. They loved that in Germany", adding he wrote it three years previously, and "I stand by every song or word I've ever written".
"Deutscher Girls" appears to have been inspired by The Night Porter, a controversial 1974 film. Made by the Italian director Liliana Cavani, Il Portiere Di Notte starred Dirk Bogarde and Charlotte Rampling. Adam Ant was a big Bogarde fan. In the film, Bogarde plays a former Nazi, and Rampling a former concentration camp inmate, and there are flashbacks to the Second World War. In the song, the roles are reversed, Adam Ant told Sounds: "It's not about concentration camps. It's about a guy who falls in love with a girl - a member of the Nazi Youth Organisation".
The problem he referred to was probably due less to this song than to his penchant for the swastika, which is actually illegal in the new "democratic" Germany, as it was in then West Germany.