Proposal: It's impossible to make peace with a city-state if the player has declared war on them in the same turn. This only applies to active war declarations on the city-states, not to wars caused by CS alliances.
Rationale: This is done to prevent the exploit of repeatedly declaring war on a city-state, attacking them with ranged units and making peace, giving the CS no chance to strike back.
Rationale: This is done to prevent the exploit of repeatedly declaring war on a city-state, attacking them with ranged units and making peace, giving the CS no chance to strike back.