In a recent game, I noticed a fellow kingdom settled a city uncomfortably close to my territories, and so I went to war with that kingdom, captured his city well before it had any significant defenses, and a season or two later bought a peace treaty with gildar and diplomacy points.

There seemed to be no long consequences of this action, as it really wasn't long before we enjoyed a "Close" relationship.

Should there be a more permanent memory of conflict that makes other factions more wary of those they've fought in the past? It just seems too easy to me to snatch strategically important city then make peace.