oops - pressing wrong buttons.
anyway has anyone tried this: since attitudes take a hit every time a city gets razed, why not build a supply of settlers, say 1 per city, whenever you are at war - this should not take long as long as you are at least out of the ancient era. plant fresh juicy cities on your borders, don't bother trying to defend them and just watch your opponent's opinion poll results take a huge hit.
Obviously this could be a really stupid idea. But never mind eh?