You could keep the "admin" roles and rules as you've already used them. And add a new role for each town 'moscow', 'london', etc.... In your controller, call a checkAccess in your action methods like in the following example.
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.