Diplomatic pressure is currently woefully documented limited functionally. When you accure enough diplomatic pressure (how?) you are able to make a demand from the pressured empire  (okay...) under the threat of war (wait, what?!) if declined.

This isn't diplomatic pressure; this is just making threats.

We already have the 'force truce' ability in game: pacificst factions can force truces with cold-war status empires.

Why doesn't diplomatic pressure, once accured, allow for similar 'forcing' of agreements (open-borders, trade-agreements, research-agreements, etc.)? I'd steer clear of forcing trade of strategics or luxuries (this seems a bit too much taken out of the hands of the player) but the idea that sufficiently disparate influence can brute-force diplomatic agreements such as the above, even if they are not in the best interests of one party, has both precedent in the game and plays a much better functional role than simply the ability to make threats backed by military might.

I'm resurrecting this thread because the currently implemented of diplmatic pressure, while improved in many respects, remains... well, bullying - albeit in a structured way the AI can understand, and that doesn't lead (immediately) to a war declaration, though the optimal play certainly is so, given how punitive many of the demands are (more than 10% hits to FIDSI is huge!). It's probably better to be in a pseudo-cold war status than having to choose between handing over resources or techs, or suffering huge punitive measures to your own economy. But at least it lets two peaceful empires wage a war of influence.

I've created an idea here to add positive diplomatic demands from pressure, as I originally outlined in this thread. At a basic level, this should use things that already exist: make peace (from cold war), open borders, trade/research agreements. Other ones could be added. 

This would make diplomatic pressure include encouraging someone to be your friend (or at least act like it!) - "Either we can both benefit here, or you'll have to pay price". This is a much more interesting problem for the recipient, and adds to the existing theme of seduction in various peaceful mechanics (Unfallen vines help you, Lumeris trade helps you - but it also helps your opponent... what to do??).

This is much more in the spirit of diplomacy and pressure, as opposed to just...well, bullying. The idea is that these basic examples are already in the game and so quick and easy to implement. This would hugely enrich diplomacy and 'real politik' as opposed to just forcing your opponent to pick the worst of two bad options.

(I'd rather see the bullying ones toned down, but that's a seperate discussion.)