'Back in the 16th and 17th centuries, two-thirds of the Danish kingdom’s income came from taxes paid by every ship passing through the Øresund strait (‘The Sound’), the only exit from the Baltic Sea. Each ship had to declare the value of its cargo – and if the Danes thought they were understating it, Denmark had the right to buy the entire cargo at the declared value.

The Danes don’t do that any more, but they still don’t like to be jerked around. They were quite cross when unidentified drones forced them to shut down their airports on several occasions late last month, and Prime Minister Mette Frederiksen said that Russian involvement could not be ruled out.'