Of course the rebelliously dirty Udo gets his nose out of joint when the PEACH says it.

You notice Babette is convincing this man by sharing a sense of duty with him. For all he claims he doesn’t want anything to do with the military service, we have to remember where he grew up and how.  Germany was part of the German Empire, which had been founded in service to the country.  Noblemen were expected to put in their time either in the military or the bureaucracy, and to improve the life of their people.  Of course, humans being so human, this wasn’t always something most German noblemen could keep up to standard.  It’s the usual problem with the pure ideal and the material we get to try to meet its frankly impossible demands.