 What is a potential risk of cities seceding from their nation-states?
What cities in the post-Brexit era could learn from a 14th-century trading bloc As you fly from the country now known as Germany to Britain, the coastal geography of northern European cities gently unfurls. You can see where the sea smacks into them, or where yawning estuaries unfold like funnels between green and brown city and choppy blue water. You can track the snaking rivers and canals that form unrepentant umbilical connections to the settlements set a little further inland. By their nature cities along coasts and rivers developed so they could be open to trade with each other. From the middle of the 13th century, and for some 300 years after, many settlements dotted along this route formed the prosperous Hanseatic League, a European trading confederation of market towns, before the rise of the nation state led to its dissolution. The Hanseatic League is not well known, and today it lives on most prominently in the name of the German national airline Lufthansa, literally the 'Hansa of the skies', whose planes you can look out of – and down towards the Hanseatic cities – on the short journeys between mainland Europe and Britain. The letters HH on the number plates of cars in Hamburg stand for Hansestadt Hamburg: another proud little memory of this hidden history. In the traumatised atmosphere of post-Brexit Britain, it is worth remembering the Hanseatic League.
 Ideological differences between city and rural dwellers could grow farther and farther apart.
 Rural areas may see a rapid economic decline.  Ideological differences between city and rural dwellers could grow farther and farther apart.  A food shortage could arise if the rural areas refuse to trade with the city that seceded.  Rural and city dwellers may decide to engage in warfare.