In 1993, on the eve of black majority rule in South Africa, Time magazine asked Nelson Mandela if economic sanctions helped speed the demise of the country's apartheid system.

"Oh, there is no doubt," Mandela said.

Throughout his 27 years in prison -- and until he became president of South Africa -- Mandela unequivocally supported sanctions as a weapon of global justice. Yet we've heard almost nothing about that legacy amid all the paeans to Mandela, who is being buried Sunday.

That reflects our cynicism about sanctions. From Iran and Syria to Cuba and North Korea, the conventional wisdom goes, American and international sanctions haven't necessarily accomplished their goals....