In the industrial heartland of Normandy, more than 100km (62 miles) away from Paris, lies the small town of Cleon. Home to fewer than 5,000 residents and a Renault factory, the town and its environs are a near-perfect reflection of the current state of France’s rust belt, where economic activity and jobs are dwindling – the factory’s workforce has shrunk from almost 5,000 to 3,124 in 10 years. Yet the planned arrival of an assembly line from Chinese firm Shanghai E-Drive next year, in...