The scent of nationalism was present in the former-Yugoslavia before Vladimir Putin effectively assumed power in Moscow. Already during the early stages of the conflict in Bosnia & Herzegovina, "BiH" solutions were being fashioned in the hope of, well appeasing is perhaps an appropriate term, those leaders in the region but also Moscow who saw feudal nationalism as the vehicle to replace authoritarian communism.
The problem with the United Nations is that it's a unity of entities defined by their hatred of one another and committed to the perpetuation of "the scourge of war." We won't begin creating global peace until we learn how to bypass nationalism and the single, unacknowledged agreement binding nation-states to each other: the inevitability of war.
Countries exist because people are willing to die for them. It is the unusual quality of nations, shared only by families and tribes, to command such loyalty. The same can't be said of other entities like villages or businesses or trade pacts or continents. Until recently it seemed as if the European Union fell into this latter category as well.