when populations are separated from each other, different cultures will arise as each group develops independently of each other, under varying conditions. criminal organizations, like governments, set up barriers, separating populations that would otherwise mix, through the aggressive enforcement of turf boundaries, more commonly referred to as "borders".
governments, the groups responsible for the arising of these artificial cultures, then use the cultural distinctions to stir up the xenophobic nationalism necessary to endear the populace to the government exploiting them. this tailor-made culture enables the state to induce fear and servility by worrying them with such collectivist specters as "the russians", the "muslims", the iranians", "illegal immigrants", "communists", "fascists", etcetera, ad infinitum.
once citizens are scared into sufficient compliance, the state can safely undertake its schemes of power-grabbing and public looting. it will justify shifting stolen (taxed) money to politically connected defense contractors for creating the necessary tools to extend empires by citing the need for "national security". it will remove competition from foreign-owned companies to favor politically connected domestic businesses in the name of "saving domestic jobs". in the name of increased power, it will claim the need to spy on citizens in order to uncover "terrorist plots". when, inevitably, the measures taken prove ineffective, the state will use the same rhetoric to ratchet up their power even more. mencken put it like this:
The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, all of them imaginary.all because of the fear of the ever-present, non-danger of foreign predators, governments are able to run roughshod over their victims (who pathetically cling to the very state they are victimized by as it positions itself as a savior), foreign and domestic. the sad part is that all those people that are the subject of "nation A's" fear are on the other side of the border, themselves made fearful by similar rhetoric promulgated by the government exploiting them. so the world is full of artificial cultures, all staring at one another, suspicious and alarmed of the evils lurking across borders.
in fact, all of this is fictional. people in every place, regardless of culture are, by and large, interested in nothing more than living their lives as best they can. they all go to work in order to produce for themselves and their families, they all want to be comfortable, they want peace, they want health, they want happiness.
apprehension may be misplaced, but they all have at least one good reason to fear evils from across borders. those evils are not manifest in cultures, but in the governments that manipulate them. the only goblins that should garner more fear and loathing than foreign governments are domestic ones.
like monsters in the closet, the state's existence requires that people have fear. similarly, flipping on the light switch of awareness makes them all disappear.