History is Now, the big new exhibition at the Southbank Centre in London, is meant to address British postwar history. It does not do so. As a Scot who voted ‘No’ in the referendum I found the experience of visiting this show profoundly depressing. I left with an increased sense that a ‘British’ identity has become problematic, dislocated and fragile, and that the ties that bind the countries that make up the Union are coming undone.