The lightboxes of the 50-year-old Canadian artist Jeff Wall regularly present surprising collisions of satire and horror, horror and pedagogy, as in Dead Troops Talk (A Vision After an Ambush of a Red Army Patrol, Near Moqor, Afghanistan, Winter 1986). His pictures are made using a camera, but he claims that the ways of thinking that inform them are closer to film editing than to the tradition of fine-art photography and the classic print. They are large-scale transparencies illuminated from behind (a strange idea, this: pictures that can be turned off when not being looked at) in which images from separate shoots are digitally combined. Equally strangely, like horror films, they invite us to ask "how did he do that?" while simultaneously reintroducing strong claims for subject matter. Part of the fascination of Wall's images is that they utilise the glamour of new technologies and the production values of advertising for entirely unexpected, sometimes shocking results. Each stone in his mocked-up Afghan ravine appears to have been arranged with the care that artificial-food manufacturers expend in gluing sesame seeds on the ideal bun. The corpses' experience of maquillage is clearly comparable to the make-up ordeals one reads about in interviews with film stars. But the subject of Dead Troops Talk sticks in the throat.
One way to avoid confronting why artists choose discomforting subjects is to use the old critic's trick, and say "it's all been done before". Wall seems to invite this approach, as he studied art history at London's Courtauld Institute in the early Seventies; he would almost certainly have seen that there is a precedent for depicting dead soldiers as undead. Jean-Antoine Gros's Napoleon on the Battlefield at Eylau depicts supplicant and liberated Poles and Lithuanians around Napoleon (who wears an expression Sir Kenneth Clark described as characteristic of victorious generals: "Would that I could have been spared this victory"). The trouble and the triumph of the picture, however, is that the foreground is entirely occupied by dead soldiers in a confused heap. They are Gros's tour de force: drifts of snow collect in their clothes and their hair, and their skin is discolouring in death. One, however, is alive and extends an arm to Napoleon: a sudden and surprising indication to the viewer that the dead will not be silenced.
So art history can definitely help. But Dead Troops Talk is speculative, rather than propagandist with an undertow of doubt. It's a representation of a community of the dead: speaking, taunting, thinking, arguing. Wall has said of it: "I attempted to create an image of a way a subjected people might try to build a space for themselves." But what sort of space do these pawns of imperial ambition have? The picture is set, we are told, in 1986, three years before the Soviet withdrawal from Afghanistan and the end of the Cold War. Seen in retrospect, these dead troops are already on borrowed time.
Wall is probably a didactic artist, though he guides viewers towards educating themselves, rather than spelling everything out. Here he points out the limitations of that easily assumed retrospective glance at history, and shows the undead of the recent past, trying to speak. To the left he includes a figure of a young Mojahedin fighter, who appears to be alive, trying to bag anything worth having. The viewer, scavenging, carrying on with life: a bridge to a present in which land mines are an aspect of the everyday.
Wall is not always as dark as here, and can even be delightful - as in A Sudden Gust of Wind (After Hokusai), which will also be in the Whitechapel's forthcoming exhibition of his recent work. Of it, he has said, "I always try to make beautiful pictures" - but a vivid sense of the grotesque looks set to dominate.
! Jeff Wall: Whitechapel Gallery, E1 (0171 522 7878), 13 Mar to 5 May.Reuse content