>>214079972
that is a good point, but the thing about zombies is they don't die without food. they spread and reproduce. you can't sit inside of a castle forever. and soon you find yourself trapped.
if you want to focus on infrastructure then the USA might be better off than europe due to having massive buildings with helipads that can pretty effectively be blocked off from zombie invasions. I think army bases might be able to be reinforced pretty easily too.