Do Economic Sanctions Work?

Just this week the United States government was able to convince the UN Security Council increase economic sanctions on Iran over its nuclear program. As scary as a nuclear Iran can be, there's a lot of evidence that economic sanctions do not have that high a success rate. Here's a chart from a paper from the Peterson Institute for International Economics:

Even getting modest policy changes happen 51% of the time. This is important when you consider just how many nations the US currently has sanctions on. I'm not suggesting sanctions never work, clearly that's not the case. I am suggesting there is a better way, the opposite of sanctions, trade. As I've mentioned before, trading with other nations is more likely to make us allies. Compare our relationships with Cuba and China. The one we have opened trade with has Westernized their economy, and in some ways their culture, radically in the last 15 years. The other is still one of the few remaining completely communist nations. Bad for Americans (cigars and beaches) and bad for Cubans (poverty and tyranny). Sanctions inherently hurt the poor working citizen, where as the political elite, who are actually those we seek to impact, can easily weather financial hardship. You are unlikely to shame them into submission. In fact, economic sanctions may actually be increasing support for those you wish to exert pressure on.