Realism in the art of the twentieth century is striking for its diversity. Although not bound together stylistically or by a manifesto of intention, a common thread in realist art is a commitment to the modern world and to things as they appear, whether it be the domestic claustrophobia depicted in Sickert's 'Ennui' or the social observation of urban nightlife in Weimar Germany in the work of Christian Schad and Georg Schrimpf. James Malpas examines the so-called 'socialist realism' of Stalin's Soviet Union and the condemnation of artists and works not conforming to the acadmic-realist scruples of Adolf Hitler. With the triumph of Abstract Expressionism in the 1950s realism may have been thought outmoded, but its varied and vibrant quality was to be revealed in the 'Pop Art' backlash in the United States and Britain, in the work of David Hockney, Richard Hamilaton, and Andy Warhol.