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.

Russia went from selling their oil on the world market at competitive prices to selling to mostly 2 customers at heavily discounted prices. And Russia is going to use barter now because of financial sanctions on Russian oil buyers.

All Russian currency reserves are frozen, and the interest these reserves generate are given to Ukraine to buy weapons.

How is Russia economically better now than before Feb 2022?

Russian industry is operating at only 81% capacity, largely due to labor shortages, which make sense considering that about 1% of its labor force join the military every other month. Russia is losing tank barrels, artillery barrels, and infantry fighting vehicles more than 10 times faster than it can manufacture new ones. It will likely never be able to obtain a third rotary forge, required for barrel manufacture, to expand its capacity. It has almost entirely cannibalized its old, defunct Soviet era stock. They are being kept afloat by China, NK, and Iran, but with a much-reduced capacity, and often much lower quality. For example, Russia relies on China for 70-80% of its microchips, but China is dumping defective microchips on them with a 40% failure rate.

Sanctions have absolutely had significant, direct, measurable impacts on Russia’s ability to wage war and sustain war.

https://www.themoscowtimes.com/2024/11/21/half-of-russias-ai... https://jamestown.org/program/russia-exhausts-soviet-era-arm... https://www.reuters.com/world/europe/what-where-are-russias-... https://archive.ph/c17pk https://www.atlanticcouncil.org/blogs/new-atlanticist/is-202... https://www.csis.org/analysis/how-sanctions-have-reshaped-ru... https://www.rusi.org/explore-our-research/publications/comme... https://osintforukraine.com/publications/microchips https://www.theregister.com/2022/10/18/russia_china_semicond...