Crossing the Channel in the middle of the World Cup month, one will notice that while English flags are just about anywhere, French flags are no more visible than when it’s not the World Cup, i.e. not at all.
I can’t think of a very convincing explanation for this lack of display of French patriotism. It’s obviously not just about sports and flags. Nationalism is always more visible in England. One reason might be that the French and the English place patriotic values in places where they do better: history (especially military) for England, culture (food, tourism) for France. Another might be about regional identity in the UK. For historical reasons people have been keen to mark which home nation they come from (Scotland, Wales, etc.), which is why flags are often visible, even when it’s not the World Cup. In France, where the policy has long been to erase the most important aspects regional identity, there’s very little of flag waving as a result–Corsica and Pays Basque being obvious exceptions.
A taxi driver yesterday told me that in Germany and Spain, there was a lot of flag pride about, too. So there must be more than what I guess here.