In my current game I'm playing as Japan aiming to become a merchant republic. As my trade range is somewhat lilimited and I'm trying not to blob I've tried to maximize my sphere of influence by carefully by releasing inherited countries and creating vassals near temperarily held provinces (I can add a country/vassal to my sphere while I share a border; plus I'm hanging on to conquered CoTs until I can switch governments to MR). This has worked well so far, but I keep losing countries from my SoI once their military grows too large compared to my own. So a few questions:
- Is there an Event for countries leaving my SoI?
- What are the military requirements for keeping a country in your SoI?
- Are there any economic requirements to be aware of?