Mark Liberman's point that few disputes are based on "different (mis)understandings of propositions, as opposed to different interests and goals" is of relevance to another linguistic issue. Some people do not regard linguistic diversity as a good thing. Their response to language endangerment is that it would be a good thing if we all spoke the same language, or if, at least, only a few major languages were in use, because we would all understand each other better and this would lead to fewer wars and disputes. The implicit premise of this argument is the proposition whose dubious truth Mark points out. A similar argument is made by the "English Only" movement in the United States, who believe that the use of languages other than English is somehow divisive. A good example of the fallacy of this proposition is Somalia, which has no effective government and is for practical purposes divided into regions ruled by warring clans and bandit gangs.The great majority of Somalis speak Somali or the closely related Maay; communication isn't their problem. Similarly, one of the longest-standing and tensest border standoffs in the world is that between North and South Korea, whose citizens speak the same language. A single world language would in all probability do very little to advance peace.