This question already has an answer here:
When being told
Oopsies, it seems we have squashed one of your favorite city-states.
or similar niceties by an AI opponent, is there any diplomatic or other effect for responding with "You'll pay for this" or the nicer option such as "We won't let this divide come between us"?
The dialog choices seem to offer a chance to shape the relationship with the other leader. However, the diplomatic tooltip hints never mention the responses.