NATO Secretary General Jaap de Hoop Scheffer announced that Macedonia was not invited to join the Alliance, due to its name related controversy with Greece. [...] Greek officials argued that Macedonia need to choose another name for their nation or at least add another adjective to it.
Macedonia has long been maligned by its neighboring countries of Bulgaria, Serbia, and Greece, all of whom have argued at one point or another that Macedonia rightfully belongs to them. Greece's claims are based on a) the fact that there's a province in Greece called Macedonia, and b) a long-standing resentment over the lost empire of Alexander the Great of Macedon. Of course, there are plenty of cases like this that haven't caused such petty tensions (New Mexico in the US vs. Mexico the country, Moldova the region of Romania vs. Republica Moldova) and outright rejection from a treaty over naming concerns. Bulgaria and Serbia have better claims on the territory, anyway – the Macedonians are Slavs like the Bulgarians and Serbs (unlike the Greeks), and Macedonian is little more than a dialect of Bulgarian (or vice-versa, depending on how you want to look at it).