It was the original forever war, which went on interminably, fuelled by religious fanaticism, personal ambition, fear of hegemony, and communal suspicion. It dragged in all the neighbouring powers. It was punctuated by repeated failed ceasefires. It inflicted suffering beyond belief and generated waves of refugees. No, this is not Syria today, but the Thirty Years' War (1618-48), which turned Germany and much of central Europe into a disaster zone...