I haven’t played Civ6 since release but I’ve really been jonesing for that kind of game so I fired it up last night. Had a super positive relationship one with Civ (China, I think?) for a long long time. They were Friendly with me, we had a bunch of trades and trade routes with each other… and then he just declared war. We weren’t crowding each other and I hadn’t had a chance to build much in the way of Wonders, so I couldn’t see any reason he’d choose to do it.
The war was quick because apparently the AI still sends it’s Great Generals unescorted in the vanguard when attacking? I don’t think it’d be very hard to code the AI to always keep a general attached to a troop. Sad to see such low hanging fruit still hanging there since Civ5.
Anyway, after I demolished his entire army with an archer he sued for peace and went right back to being super friendly with me. Haven’t had any wars with him since.
I did have an Alliance with Scotland that lasted, but they were on a different continent and completely useless. Still, at least when things get to an Alliance state it seemed to stick pretty well. That may not be the case if they were located near me, though.
The war AI deficiencies wouldn’t bother me nearly as much if your “friends” weren’t psychopaths that’d attack you (seemingly) depending on a dice roll. I’m playing with a self-imposed rule where I’m not allowed to declare war or take cities so I’d happily just mind my own business if they’d only let me.