[myrmidon]

I agree with a lot of what you say, but I think one aspect of sanctions that you are missing a bit is that they stifle growth (especially long-term) by forcing the victim to waste ressources on unwanted/inefficient industries or convoluted procurement.

Basically, you are hurting your own economy (non negligibly in the EU-Russia case for example!) to make sure that you outgrow the sanctioned opponent, making any future conflict more favorable for yourself.

There is a lot of evidence that this aspect works pretty well; even if you can sidestep the sanctions with middle-men or substitute local industry, this always comes with additional friction/costs (just consider German synth fuel industry during WW2-- that was an insane amount of ressources that could've gone into planes or tanks or somesuch instead).

For an example of sanctions directly effecting diplomatic outcomes, just consider Jordan over the Gulf wars: They stayed neutral during the first one (which Bush did NOT like), got sanctioned (without western citizens even noticing too much), suffered a lot from that, then during the second Iraq war they basically cooperated with the US (grudgingly!).

I think it is difficult to find many clear examples for this because sanctions typically mostly work as a threat, and being put in place is a kind of failure mode for them already.