I also would like to see the borders defined by our cultural borders actually mean something other than as an indicator to which way the influence is pushing. I really see no reason to add *another* superficial line.
More diplomacy options is definitely the way to go here, something which has been asked for before.
The current trade embargo button, which as far as I know just keeps that ai from creating trade routes with your worlds and removes any that are currently there is the basis of what I'd like to see.
In the Foreign relations sceen you have a new tab, Policies.
- The trade embargo button can be moved there, forbidding trade routes.
- Ban their war ships from entering your territory. (Foreign planets under your influence would be an exception, they control that planet, and ships built and docked there are not technically in your space yet)
- Ban their constructors from entering your territory. (Influence would then have to be pushed progressively, no more squatting influence starbases right outside your homeworld)
- Allow or deny right of passage (Applies to warships or constructors from the above two options. Right of passage being defined as auto-moving to a location that is outside your territory, much like moving back into your ship range when a wormhole teleports your flagship to the other side of the galaxy)
- Set a tax for entering and staying in your territory (this would apply to all ships or only unarmed ships without constructors if the above two options are set)
- Set a tax on starbases and planets they control that are within your territory (The higher the tax the more their relation with you goes down and the less your influence affects their people. ie the border there may change enough that they would no longer BE in your space, so some balance might have to be struck if you chose that option, even if you had a far superior military and they wouldn't go to war with you)
Of course all of the above options would only apply to a civilization that you are not at war with. Breaking these policies would create an instant message from you to them or vice versa stating they have 1 turn to remove their ships or they might as well declare war. War would be declared from the policy breaker the next turn if the ships aren't removed.
You would not be able to apply these to allies of course.
To give these options their full utility, there would be options in the diplomacy screen to ask for a change of policy from one of the civ's (ask for right of passage so you can attack a civ on the other side of their borders for instance).
Or telling a civ that he'd better let your contructors in "or else", much like demanding tribute.
Some would be set from the start of the game (the bans against constructors and warhips and deny right of passage). Others you can set later and will result in lower relations with that civ. Lifting bans would result in slightly better relations, though if you had a weak military and decided to allow their ships to move into your territory to improve relations so they wouldn't actually go to war with you quite yet might delay war a few turns, but would allow them to get into a better position to attack, so might not be advisable
Including all of that and adding more ai so they don't inadvertently go to war with you because they tried to move a constructor into your area, I don't expect to see anytime soon, but put it on my wish-list.
