I actually tried friendly. I would have liked to have declared friendships for the boost to great people production. Some of the distant AI's started denouncing me, and when I looked at the diplomacy report the only negative was "They have denounced us!" I think the denouncements were just to impress each other; I mostly ignored them. I sold them luxuries at a discount and I voted for most of their resolutions, and they weren't a threat. But it meant very few research agreements.So much for the friendly approach.
Rome and The Aztecs were obviously going for domination (that didn't work so well for Monty) and I was the next target. Plus I needed generals and admirals for that Nobel Prize thing.