when do sanctions work?

A blogger at the Washington Post draws on academic research to conclude that economic sanctions have worked only 13 times since the end of World War I. It's an interesting list, notably because most of the examples were ones I never heard of. They also were for comparatively small changes by the sanctioned countries. 

The list doesn't include the anti-apartheid sanctions against South Africa, which I think proved effective. Nor does it include the U.S. refusal to support the British pound during the Suez crisis, which forced Anthony Eden to back down.

The broader lesson is that multilateral sanctions are more influential, if not decisive, when they are imposed by a large segment of the international community. That's what has worked on Iran, And it's why Russia will feel little pressure no matter what the U.S. does until the big European economies crack down, as they so far have been reluctant to do. "Feel good" sanctions that aren't widely shared only punish the sanctioners.