Quoting willie sanderson,
As well it should.
Of course, but only after five turns have elapsed.
Perhaps one faction, either now or in future, should be able to break this rule though and raze instantly (maybe on capture only) as a suggestion.
Attila in CiV G+K has the ability to raze cities at double speed, which makes him a great choice for going on a rampage, since he doesn't get bogged down by the unhappiness of capturing/razing cities. In CiV, it is an interesting differentiator and I enjoy playing as Attila when I feel like burning stuff to the ground.
However, in FE, there really is no negative to holding cities (edit: there is -- reduced growth). You are never worse off by capturing a city than you were before, even if the city itself is useless due to unrest. Thus, being able to raze at double speed (say, after only two turns), isn't an interesting trait for a human player except maybe for a slight RP component.
If this trait is there simply to make one AI faction more competitive against a human, then teaching the AI to defend their captured holdings is a better solution.
