Arms embargoes are commonly used to alleviate humanitarian crises or even end a conflict, though this strategy doesn't always work. Sometimes, an arms embargo might simply lead a fighting force to use a different kind of weapon, as happened during the Rwandan genocide.
And other times, the embargo outlives its useful life. For instance, the U.S. imposed a trade embargo against Cuba in 1962, shortly after Fidel Castro seized power. Much has changed in the world since then. The Soviet Union fell more than 30 years ago, and Fidel Castro died several years ago as well. Nonetheless, the embargo still persists, although there are a number of exceptions to it.