[imchillyb]

Sanctions are not designed to coerce a populace into rebellion, in order to facilitate regime change.

Sanctions are designed to prevent an enemy government from profiting from our western economy. Sanctions are designed to bring hostile entities to the negotiation table. Sanctions curtail the worst behaviors of enemy nations because the sanctions deny those enemies money. Money is power. Little money = little power.

[int_19h]

For the most part, sanctions are designed to be "something" in the infamous "SOMEBODY DO SOMETHING RIGHT NOW!!!1!" mantra. They rarely achieve any of the goals that you enumerate, disproportionately inconveniencing regular citizens - government actors have the means and the know-how to work around them. But mob justice demands an eye for an eye, which is to say, someone must be made to suffer - and sanctions provide a way to do that, even if the people actually suffering are rarely morally responsible.