'To help the civillians we must starve them with total economic sanctions until they overthow their government' comes off as cynical and depraved (in hindsight of similar actions in Gaza, Iraq, Afghanistan and also Iran ) and i no longer subscribe to it.
I'm not sure it's about helping get civilians.
Sanctions for Iran is about limiting their economic growth. So that they are less effective should they try to attack their neighbors.
Civilians in a dictatorship are probably not entirely with responsibility for the regime actions either.
Regimes can rarely survive without supporters.