This is a big topic, so worthy of it's own thread. we've always struggled with how much feedback to provide and how to provide that feedback. Ticket 32487.
This one in particular is tough. There are 100s of causes of relationship micro-changes happening all the time. Trading, new treaties, troop movements for example. And there are so many because everyone is experiencing these all at once. When I sign a treaty with 1 region in a volatile split world between two spheres, I've just affected relationships with more than 100 other regions. We can't just put 100 on map notices or send 100 newsitems in response to this 1 action. There are also some of the causes that, if indicated, give players artificial knowledge. If you have a tank a few hexes back from the border of region B, they have a unit outside your LoS that can see the tank and seeing the tank "upsets" them, but you don't know about their spotting unit. We can't tell you why your relationship just dropped by 1%. And is 1% really significant? We also only know what affected relations "yesterday". The game doesn't store historical values.
So in order to move forward on something like this, we would need more context and examples. The main actions are the ones I listed - trades, treaties, wars and troop deployment. What other action/effect pairs are you thinking we don't report?
