The port of Calais on France’s northern coast has spent 6 million euros ($6.6 million) on facilities for customs officers, updated signage around freshly painted roads and huge extra parking lots for trucks. It may all end up being pointless. What looks like the expansion of a transit hub in the world’s busiest shipping area is more an insurance policy against upheaval from Britain’s tortuous journey out of the European Union. U.K. Prime Minister Boris Johnson is trying to get a deal over the line this week to make good on his promise to leave by the end of the month.