As a rule, I don't like movies "based on true stories," but I'll make an exception for Joyeux Noël. It's a trilingual tale of fraternization on World War I's Western front, and nicely shows the contrast between individual decency and collective brutality. Watching it immediately brought to Tolstoy's essay "Patriotism, or Peace?", which in turn brought to mind Overcoming Bias:
If an American wishes the preferential grandeur and well-being of America above all other nations, and the same is desired by his state by an Englishman, and a Russian, and a Turk, and a Dutchman, and an Abyssinian, and a citizen of Venezuela and of the Transvaal, and an Armenian, and a Pole, and a Bohemian, and all of them are convinced that these desires need not only not be concealed or repressed, but should be a matter of pride and be developed in themselves and in others; and if the greatness and wellbeing of one country or nation cannot be obtained except to the detriment of another nation, frequently of many countries and nations - how can war be avoided?
And so, not to have any war, it is not necessary to preach and pray to God about peace, to persuade the English-speaking nations that they ought to be friendly toward one another; to marry princes to princesses of other nations - but to destroy what produces war. But what produces war is the desire for the exclusive good for one's own nation - what is called patriotism. And so to abolish war, it is necessary to abolish patriotism, and to abolish patriotism, it is necessary to it is necessary first to become convinced that it is an evil, and that is hard to do.
This is the kind of idealistic talk that believers in Realpolitik typically scorn. But a hundred years later, Tolstoy seems more perceptive than ever. In the modern world, how often do countries actually have anything to fight about?