Why can't we talk to a civilization with which a war just started for a fixed number of turns? (Btw where can we even see what that turn limit even is?) What's the point? Especially because the AI is not limited by this; they can suggest a cease fire much earlier than that limit.
This was tolerable before but with the new war goals feature in Warlords, it essentially makes "War of Defence" all but useless. Let's say I want to destroy some communication starbases because a foreign influence starts to overtake my planet. My only goal would be to destroy these to buy some time to reinforce my own influence. So, a "War of Defence" would come to mind. So, I start the war, destroy the starbases in the first 10 turns, then... I wait so the turn limit expires and I can negotiate with that empire. What's worse is that I have to defend my planets from enemy fleets while I wait, so the war "Progress" goes over 100% very quickly. My whole empire cries out for peace, but I can't end the war, because I cannot talk to the other participant for who knows how many more turns.
This problem is not limited to this particular case, the war progression fills in way too fast from just ship combat. My suggestion would be to either only count starbase and colony conquests towards the war "Progress", extend the Progress cap for all types of war, or, what I personally feel would be the best solution, allow negotiations the moment the "Progress" reaches 100%. That or just remove the minimum war duration from Warlords all together.