You could return - which essentially means: 'no rewrite', but I don't know whether that's supported in a maps R combination. Better may be to check with RewriteCond ${dbapp:$1}! ^$ or something that it doesn't contain an empty string.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.