Great thread, but i must say this is absolutely ridiculous..
"You can either tell them you’ll do as you please, in which case you incur an additional penalty, or you can apologise and promise not to spy on them again, in which case you won’t receive an additional penalty, but if you’re caught spying on them again in the future."
"If you bluntly ask them to stop spying, you will incur a diplomatic penalty, whereas if you let the transgression slide, you receive a diplomatic bonus; the AI is pleased that you are willing to forgive them."
So if you spy on the AI and gets caught, you get a penalty to their relationship if you tell them 'meh, we spy on whoever we want'. Sure, fair enough. But the AI does NOT get any penalty for asking you to stop!! Now, if you catch the AI and ask them to stop, YOU incur a relationship penalty!! But if you say 'oh its quite allright' you don't..
This is ridiculous, basically hardcoded game mechanics to make the player be bullied by the AI.. Since we can't even play on equal terms. The AI can ask the player to stop, with a diplomatic penalty if we dont stop. But the player can NOT ask the AI to stop, getting a diplomatic penalty ourselves just for even asking.
I think it's quite a reasonable demand to ask that someone stop spying on you, how the hell does that translate into a diplomatic penalty for the one being spied on, when the AI itself has the right to ask the player to stop without recieving any penalty itself.
So unbalanced, so unfair..
This is why diplomacy in Civ 5 always falls flat and feels gamey as opposed to dealing with other leaders. Because there are weird artificial lopsided rules. So if we wanna be peaceful to the AI we can't even defend our own cities from espionage, we can't even ask them to stop spying on us. Ridiculous. Bah..