Do economic sanctions actually work?

It depends on how success is measured, and researchers disagree, partly because success is hard to define and harder to measure. The efficacy of sanctions in achieving their intended goals is a subject of debate. One well-known study by Hufbauer, Schott and Elliott found that 34 percent of the cases it studied were successful. When Robert A. Pape examined the same study, he found that only 5 of its reported 40 successes were actually effective, reducing the success rate to 4 percent.

Part of the problem is that a change in a government's behaviour has many causes. It is hard to tell whether a regime changed because of a sanction or because of its own instability. Other studies measure something different: Neuenkirch and Neumeier found that UN sanctions reduced targeted countries' GDP growth by an average of 2.3 to 3.5 percent a year, while unilateral US sanctions reduced it by 0.5 to 0.9 percent a year. Morgan, Syropoulos and Yotov describe sanctions as increasingly frequent but inconsistently effective.

Why impose them, then? British diplomat Jeremy Greenstock suggests sanctions are popular not because they are known to be effective, but because there is nothing else between words and military action if you want to bring pressure on a government.

There are costs too. Sanctions have been criticized on humanitarian grounds, since they hurt a nation's economy and can cause collateral damage to ordinary citizens, and imposing them also affects the imposing country's economy to a degree. Since the mid-1990s the UN Security Council has generally refrained from imposing comprehensive sanctions, in part because of the controversy over the sanctions against Iraq.