Oh, there seems to be a latent assumption that: friendship and selfishness are mutually exclusive concepts. Far from....a good partnership can provide that, ultimately, the only enemy left to defeat is your partner.
To clarify: all I was trying to say is that sometimes the best way to play to win (selfish motivation) is to forge strong partnerships with other civs. Humans understand this. This AI seems to avoid cooperative partnerships even in situations where it would be in its best interest whether in the short or long-term.
Example: In the game I'm playing, Greeks and the Ottomans have been going at it, back and forth all game long. Both are minor threats in terms of their position relative to my borders.
The Japanese are positioned to south of both the Greeks and the Ottomans and quite a distance from me (we are no threat to each other). The Japanese are very small but their positioning would make them a valuable strategic partner to me. Also, given that the Japanese have had numerous wars with the Ottomans, I would also be a valuable partner from the Japanese standpoint.
So, I have tried to reach out to the Japanese to strengthen them relative to everyone else on the continent and to hopefully have a partner against the Ottomans. It would be in both our interests.
I've supplied Japan with a substantial amount of GPT for 120 turns or longer, strategic and luxury resources, and I've generally agreed to their requests. Yet, they remain hostile with me. wtf? We both hate the Ottomans, we've both been at war with the Ottomans, I treat them with gifts and respect.....yet they're hostile, they won't make fair trades, they don't want research agreements, and they want me to pay for open borders even though closed borders prevents them from opening a second front against the Ottomans during their wars..... so dumb!
The AI (in this case Japan) should realize that their best interest resides in buddying up with me for the time being -- riding my coat tails a more powerful position in the continent -- eventually using their preferred status with me to negotiate mutual war against Ottomans, thereby expanding their empire.
By embracing a strong strategic partnership with me Japan could easily become the #2 power on the continent. As the #2 power, Japan might one day be a rival to me. As it is, Japan is weak and stupid.