[rmnunez]

You're right gramps, the sanctions didn't work in Iraq either, they don't work anywhere. They didn't work in Iraq because Saddam was fabulously wealthy and felt no hardship, and because despite the suffering of millions of his subjects, they could bring no pressure to bear against him for change to reduce those sanctions. This is why sanctions don't work well in Cuba, Iran or North Korea either.

Sanctrions aren't often resorted to, usually when there's some dispute between governments, the diplomatic process is effective in resolving this. I suspect there are cases we never know about, when the dispute cannot be resolved and then economic pressure is applied effectively to bring them back to the bargaining table diplomatically.

The US is the most important market for most countries, so if the US threatens to impose restrictions, add tariffs or somehow slow things down, this will immediately mess up things in the threatened country. Countries which are focused on a single major export likely face very substantial effects from any US sanctioning. Countries which have diversified their economies and have developed other markets can cope better.

But the effectiveness of sanctions depends on the responsiveness of the sanctioned government to the hardships resulting to its population. If millions died in Iraq as a consequence of US sanctions this is a measure of Saddam's viciousness, not of the US', after all, Saddam could induce the relaxation of those sanctions whenever he wanted, but never did. Look at Cuba, if Castro wanted to restore economic relations with the US to what they were like in 1959, all he has to do is pay a relatively insignificant amount of compensation to a few hoteliers who got expropriated by the communists. Its a few million in exchange for billions in trade, why not?