How to do diplomacy? Keeping them off of my back.

This is a problem for me, i have done several free for all games against 4 AI's.  With out fail, at about the one hour mark, all of them are attacking me with sizable fleets including there capital ships.

I have tried to do the missions, but they mostly require offensive measures, which is hard to do early in the game.  Defeat 2 or 4 tacticle or logistical structures?  Hard to do early on.  I did do a couple, but requires a couple missions to get even neutral to have a cease fire....

Any ways around this team up ganking me early on?

I have zero problem with pirates.