Assassination in current espionage mechanics would be terrible. Anyway, whole espionage mechanics now is pretty unfun and only annoying.
https://forum.paradoxplaza.com/foru...ants-good-or-bad-design.988886/#post-22213140
Please take a look at my vision of espionage in EU4 in spare time. Right now espionage is just eh. Because of this mechanics player's nation in mid-late game always has like 3 spy networks at 100% and permanent sow discontent, sabotage recruitment, slander merchants etc. It's just always on. It's unfun and stupid, there should be ways to prevent it, and small, poor countries should not even be able to infiltrate huge empires like Russia or Ottomans, because they can't even afford that. Espionage should be expensive, but strong. Just like keeping large army - large army is strong, but expensive. Espionage should provide strong "sniping" possibilities.