fcw.org server has defenders to make counter-bombing (retaliating) when bombed. Maybe we should build proper support for such a feature by introducing "Retaliate" action, and Action Auto Performer for it.
Are there other differences between Retaliate and the existing bombard action than that it won't reduce the population of the target city? If that is it #42242 should make it possible to use one of the Bombard copies. In that case all that is needed here is an Action Auto Performer.