As what we've seen with Iran, government sanctions do work to limit the country that the sanctions are placed on. These sanctions are very good as this may help force the country to be better to the rest of the world and it's own people in the close to near future.
I definitely think that government sanctions work. I think there are a lot of sanctions that the government enforces that has worked to either restrict some enterprises from operating illegal activities, to helping to protect the envinronment by reducing a company's or business' ability to conduct in processes that do so.
Government sanctions are meant to influence a certain behavior. They do not force it directly. They are effective at slowing a behavior, not stopping it. Critics of government sanctions typically would prefer a more direct, and usually military approach to influencing a behavior. While that option is much more effective, it also costs way more than just the money it takes to deploy soldiers. There are diplomatic repercussions that inevitably follow such actions and may also include more hostilities from the allies of that country.
The reason government sanctions work is because they can basically put a strangle hold on a country, state, or district. It pretty much gives the area they are sanctioning no room to wriggle around or make any of the progress they were looking to make. It's a brutal approach, but better than war.
Government sanctions do not work in the sense that they do not make other societies respond by coming into alignment with international norms. What they do achieve, however, is the destabilization of societies and the death or immiseration of countless people. We can see these effects in Iraq, in which during the 90's over 100,000 children died at the hands of US sanctions. From the perspective of the socio-pathological power structure, the sanctions are working at softening up victim nations for invasion, but from the perspective of freedom and justice loving people, sanctions are a failure of morality.