evidence: Prevlaka had been a military base for decades before Croatia won its independence, and the Montenegrin headland on the opposite, southern side of the bay is riddled with military installations--allegedly including missile sites. [...] Belgrade insists that Prevlaka is a territorial dispute to be solved by changing the international border--a position rejected by Croatia and the rest of the international community. [...] It is more than likely that the incursion is intended only as a signal that Milosevic could indeed make trouble in this little-regarded corner of the Balkans, should he choose to do so. Although Prevlaka is still a minor sideshow, great vigilance should be shown by Croatia, by NATO, and above all by Montenegro, if Belgrade's symbolic act is not to result in a general heightening of tensions on all sides.