I know a little about this; it's pretty controversial, historically, whether Western sanctions, vs. decades of civil war and violent insurrection (often backed by subvert support from the Kremlin with the CIA playing defense) in SA and neighboring states were the catalyst. There are plenty of historians / economists who would argue that sanctions made things worse for the people of South Africa (much the same is said today about sanctions against Iran). In any event, that sanctions where "the" instrument that brought an end to apartheid should not be stated as if it were a universally accepted fact.

Let's ignore how ridiculous it is to give the West the credit for ending apartheid and that the economic growth of South Africa really doesn't back up your claim that sanctions were the key.

Even assuming you're right about the cause, the success story of sanctions would be a South African economy that never recovered leading to the suffering of millions. That's what happens when they "work."

What about Cuba? North Korea? Iran? They’ve been sanctioned for decades with devastating human consequences and little to no sign of those sanctions spurring any meaningful change.

I don't disagree with you but I do wonder whether for sanctions to be successful relies a lot on the way the population is feeling about the regime at the start. If they population decides to dig in, then the sanctions start to have a negative effect (in terms of getting a desired outcome).

If on the other hand the population is already angry at the regime, maybe it has the desired effect.

Idle musing without supporting evidence.

Only the US sanctioned Cuba and while it was pretty harmful, they were still able to trade with most other countries. North Korea has China right next door as a big trade partner, and can trade with many non-US countries as well. As for Iran, from what I can tell UN sanctions really only started to ramp up in the 2010s and those did have an effect in getting Iran to suspend its nuclear program.

Edit: But to be clear, I think the US sanctions on Cuba are gratuitous and cruel. Cuba is not some rogue state and there are many worse dictatorships that aren't sanctioned. However, I think it reinforces the point that "sanctions can be devastatingly effective applied by a significant majority of the world" because in the Cuba case the rest of the world didn't agree.

> Only the US sanctioned Cuba and while it was pretty harmful, they were still able to trade with most other countries.

There were considerable limits (particularly on foreign investment in Cuba) because parts of the US sanctions regime include retaliatory sanctions on entities making use of certain property in Cuba (some of these were suspended for a while, but restored under Trump in 2017.)

The impact of sanctions against apartheid SA get talked about a lot because it's a good example of international cooperation for non-violent activism.

Unfortunately talking only about sanctions ignores that plenty of governments resisted and watered down the sanctions because the apartheid regime's anti-communist ideology.

The negotiations to phase out apartheid for a democracy began mere months after the fall of the Berlin wall. At that point the collapse of the USSR was imminent, and the apartheid regime's utility as an anti-Communist outpost had expired.