The problem we all know. Lack of real action in strat because powerblocks are building up, none are willing to wage an all out war in fear that a 3rd party or fragile alliances will break. My theory is that if factions had good ways to hurt each other without going all out/identifying themselves, they would do so.
Such a setup would open the gates of hell when it comes to who to trust, and who not to trust. Situations could quickly become unbearable, and force factions to go to all out war.
Idea is simple:
Allow clans or factions to create "secret" or black armies for backstabbing purposes
*To the enemy it would be impossible/hard to identify the owners of that army.
* Perhaps the combatants inside the army should also be secret, or it would often be a dead giveaway.
* Perhaps such armies should be harder/more expensive to maintain, relative to a normal army.
Other ways to sabotage for each other without going for all out wars.
Don't have so many ideas here, but paying to sabotage cities etc. could be an element here.
Peace is just too easy in strat!
It is carebear by nature, everyone can see who is attacking, everyone can see who is participating in battles. It needs to be dirtier to loosen up.