I must say, you are right. I believe they are not all that effective, and are destructive in many ways. I, however, do believe they were appropriate for South Africa, even though that country is being destroyed. If I would support them for South Africa, I'd sure support them for other countries, especially terrorist countries. You don't do the embargo for the country being embargoed - it's for other countries who have a tendency to follow the trail of violence. I would like to see a fense put around Syria, Iraq, and Iran. If they herded goats for the next thirty years, it would be a benefit to mankind. Other countries, who have some economic success, might become a little slower on the draw.
Again, I don't disagree with you about your opinion. An embargo may have worked against a specific country some place other than south Africa, but I don't know where. Yet, I had rather have a hard embargo for decades than to use B-52's on the population. And whatever we do, we do have to do something - and it has to be terrible. But, if it's not well thought out, we'll be just like Israel, fighting them forever. And, I don't think this will be the last horrible lick they get on us. AND, I don't think they care how many of their people die.
After the counter-attack, we should seriously consider not attacking other nations except in cases of true national emergency. Other people are going to have to be somewhat responsible for their own country, just like we have to be responsible for our own. Consequently, I believe we should make a devastating attack on terrorist training camps, possibly on the Taliban, and then we should quietly kill the leaders of the many extremist groups. They can be driven so far underground that their effectiveness will be sapped.
I don't know that the embargo worked in South Africa. South Africa was completely self-sufficient.