AT THE entrance to the old harbour, the walls of the medieval Fort Saint-Jean are freshly scrubbed. Across a high-level walkway, the sun casts lattice-shaped shadows on a modernist new museum of European and Mediterranean civilisations. Nearby, where ferries dock from Algeria, a waterfront shopping mall opens this month. Marseille, France’s second-biggest city, is trying to reinvent itself as a cosmopolitan place. It drew nearly 5m visitors last year as Europe’s “city of culture”. A five-star hotel has opened above the port. Violent theft dropped by 20% in 2013. “We have had enough of Marseille-bashing,” says Yves Moraine, leader of the local centre-right UMP. “There is a new pride in the town.” Jean-Claude Gaudin, also of the UMP, was re-elected mayor in March.Yet away from the seafront, in heavily immigrant northern districts, talk of renewal seems otherworldly. In some quarters youth unemployment is more than 40%. In the third arrondissement, the poverty rate is 55%, over twice the city’s average. Rivalry between drug gangs often turns violent. In April a youth was shot dead with a…