You will have to forgive his incapability of handling a question like this. He isn't fond of people saying he should not exist and as you can tell, he's hardly the type to kee phis temper in check.

Perhaps this will be easier to understand. Prussia was a country once upon a time. Gilbert is Prussia. After the war, the nation of Prussia was disbanded but Gilbert lives on because his people did and still do. Remnants of his country are still there and he is part of them. No matter how you look at it, Gilbert is still Prussia and always will be even though he is a little more difficult to find on a modern map.