How do you prevent AI Civs from conquering your nearby city-states in the early game?

[ruhrgebietheld]

I've run into an issue several times now where the city-states closest to my capital get conquered by an AI civ within the first 100 turns. All the AI civ has to do is produce 4-5 warriors and they easily conquer the city-state, including ones that I'm the suzerain of. Is there any way to prevent this, other than immediately declaring war on that civ and trying to obliterate their forces before they can take the city-state? I can't find anything in diplomacy that makes AI civs back off your city-states. No demands, no deals, nothing. Which sucks, a lot, because not only do you lose the benefits you were getting from those city states, you don't get refunded any envoys that you had invested into that city-state. So is there anything I can do to stop this from continually happening? Because a the moment the only option seems to be "Hope that you get lucky and no AI civ decides it wants the city-states near you early in the game."

 

[MagicCuboid]

Yeah there's nothing you can do at the moment besides denounce them and/or declare war on them yourself. If you take back the City State and liberate it you get a bunch of envoys (either 3 or 4).

It puts into perspective how powerful Barbarossa's ability is. Sure, he doesn't benefit as much from the city states he conquers, but he removes the bonus from all of his neighbors as well. I think the first thing Germany should do before an invasion is take out the enemy's allied city-states.

 

[stealth_nsk]

There's no way to prevent this in early game, but:
- It's very likely you'll have some war with nearby civ later and you could liberate the city-state any time. You'll become suzerain immediately.
- Later in the game you'll have Protectorate War CB, which is almost exploit due to its 0 base warmonger penalty.

 

[CaiusDrewart]

I'm also noticing that the AI is very aggressive against city-states. And unlike in Civ V, where the AI would often struggle to conquer city-states in the early game, this time around the attacks are usually successful. (You can thank weakened city defenses for that, I think.)

It's really silly that there isn't, at the very least, a "stop attacking that city state" discussion option. If I can tell an AI not to settle near me and not to convert my cities, I don't see why I shouldn't be able to ask them to leave my friends alone.

Personally, I would also be in favor of moving up Protectorate War CB (and indeed pretty much all CBs) quite a bit earlier in the tech tree.