The EU is an imperfect answer to an age-old question: can the people of Europe live in peace? Since the fall of the Roman Empire in 476 until the end of the Second World War in 1945, the answer has often been a bloody No. As the long centuries from warring feudal fiefdoms to modern sovereign states saw Europe and the wider world transformed, the march of jagged progress was regularly drowned in European blood. Much of that bloodshed was driven by the ideology of absolute sovereignty. For over a millennium, warlords, kings, emperors, dictators, and finally sovereign states fought…