I had this randomly the other day, I was playing as Japan on continents. I had bismarck and Washington on my continent so I figured I was going to be in for a long slog of constant war. However it didn't happen that way. I built up a decent military and just plodded along with my science. Ended up getting a science victory without anyone declaring war on me once... I was very surprised to say the least since Washington seems to declare war on me every time he can usually.
This was on king difficulty by the way, so the AI is usually aggressive
This was on king difficulty by the way, so the AI is usually aggressive