The second was Jean Vigo’s 45-minute feature, Zero de conduite (1933), which has been an inspiration to film-makers ever since it was first shown - in spite of (or perhaps because of) the fact that it was banned in France until 1945, as a threat to public order. Chaplin’s Kid is the father to a whole orphanage of cinema waifs and pools of tears shed over childhood sorrows; Vigo spawned a tougher breed.

Zero de conduite describes an uprising in a repressive French boarding school. It was made on a shoestring: the technical shortcomings are part of the charm for its natural audience of film school students, still young enough to be susceptible to its anarchistic poetry. Film was just emerging from its 35 years’ silence, during which it had hesitated between drama and the visual arts. Vigo lived in the milieu that produced Surrealism, including surrealistic experiments in cinema, and from them he learned that, although film representation is literal, it does not have to be naturalistic. The school in Zero de conduite is a grotesque distortion, the headmaster is an evil dwarf and the one sympathetic teacher is a trained clown who amuses the children with his act - including imitations of Charlie Chaplin. This is school seen from the other end of the telescope, through the eyes of the boys.

The power of Vigo’s discovery was such that his film became a central text, one of the most quoted in cinema history. Its influence can be seen most obviously in Lindsay Anderson’s If (1968), virtually a remake, though it transposes the action to a British public school and updates the boys’ weaponry. There were also enduring influences on the work of Francois Truffaut, who worshiped Vigo from the moment when he first saw Zero de conduite at a cine-club screening in 1946. The spirit of Vigo is tangible in Les 400 coups and in Truffaut’s other films about childhood, Les Mistons, L’Argent de poche and L’Enfant sauvage. The director even found a role in that last film for Jean Daste (who died on October 16), the actor who played the clowning teacher in Zero de conduite.

There was no accident in that, or in the fact that The War of the Buttons, which opened last week, ends on a shot that refers both to the pillow fight in Vigo’s masterpiece and to the freeze-frame at the end of Truffaut’s Les 400 coups. Directed by John Roberts and taken from a novel by Louis Pergaud, The War of the Buttons was originally filmed in 1962 by Yves Robert. Robert, the director who made the films from Marcel Pagnol’s childhood autobiography, still owns the film rights to Pergaud’s work and has long refused to allow it to be translated to England or America, but he was persuaded to grant permission for this version, shot in South-West Ireland.

The story revolves around the rivalry between two neighbouring villages, Ballydowse and Carrickdowse, whose children see the antagonism as a full-scale war, though fought with catapults, insults and the humiliation visited on prisoners who are sent home with all the buttons cut off their clothes. The film would have been impossible without a cast of remarkable child actors, but they are not winsome Jackie Coogans or Shirley Temples. Not only do they look and sound like ordinary children, they also act like them, being capable of betrayal, cruelty and fear, as well as affection and loyalty. Their behaviour illuminates facets of the adult world, but they remain children - and, if nothing else, more innocent because less able than adults to do harm.

The War of the Buttons is set in the late 1970s, but the rural background means that it has both a period feel and a sense of taking place outside time. According to its producer, David Puttnam, “one of the things that we tried to make clear in the film is that children are an endangered species”: most of us now grow up in towns, subject to the influence of mass media and other aspects of the urban environment, with the result that some aspects of childhood are being lost - including, as Puttnam says, the need for children at certain stages to consider adults as The Enemy.

We tend, rather too casually, to say that such films adopt “a child’s point of view”. We don’t usually mean by this that the camera moves at waist height; though a few shots, like the ones of shoes coming down the stairs at the start of War of the Buttons, may remind us discreetly that children are closer to the ground than adults. But when we talk about the child’s viewpoint, we imply that the central characters are children, and that our interest and sympathies are supposed to lie with them. In War of the Buttons, the narrative opens with a voice-over statement by one of the characters, now grown up, and ends with a coda by her, putting the main action of the film into a kind of cinematic perfect tense, as something completed in the past. John Boorman’s Hope and Glory (1987) uses just the same framing device.

The child’s gaze can be quite disturbing for adults. This is partly because children have not had the time or the opportunity to do anything very wicked, or to be seriously tested - to have become the grotesques in Zero de conduite, for example, or the warring parents in Les 400 coups - so our consciences may well interpret the gaze as critical. And we know, as Puttnam says, that they may need (from this position of moral strength) to challenge us, both for their own health and that of society. Progress comes because children, like the boy in Hope and Glory, can say of his parents: “Don’t worry, Sis, we’re not going to be like them when we grow up; we’re not like them now.”

The cinema has never so effectively used this right of children to challenge the mess made by their elders, as in films about war: directly, and starkly, in Steven Spielberg’s Empire of the Sun (1987), Andrei Tarkovsky’s Ivan’s Childhood (1962) and Elem Klimov’s savage Come and See (1985), where we watch the destruction of childhood itself by war. The assault is less direct, but no less effective, in Louis Malle’s Au revoir les enfants (1987), where the theme is also the loss of childhood: at a school in occupied France, two boys make friends; but one is a Jewish child who has been concealed in the school to save him from the Gestapo. The narrative is based on an actual incident in Malle’s childhood, but the film is not about nostalgia: as Malle has said, he made it partly out of concern about a resurgence of anti-semitism in France in the 1980s, and so as a warning to his own generation not to repeat the horrors of the past.

Not all films about war involving children show them as obvious victims. Rene Clement’s Jeux interdits (1952) is a famously oblique approach to the devastation of war, a story about two orphans who imitate the behaviour of grown-ups by making a cemetery for dead animals. Boorman’s semi-autobiographical Hope and Glory revolves around a truth understood by many of his generation: that a child can actually experience war as a liberation from normal constraints. The final scene, where the children arrive to find, to their delight, that their school has suffered a direct hit overnight from a German bomber, appears to be yet another quotation from Zero de conduite.

To adults bombsites seemed like scars on the landscape; children knew that they were in fact adventure playgrounds. They appeared as such in the first of the Ealing Comedies, Charles Crichton’s Hue and Cry (1947), where a gang of East End kids turns out to be able to read the truth behind an apparently innocent strip cartoon: the child’s eye is keener.

There is ample room for misunderstandings between children and adults, as well as for diverse viewpoints on film. The theft at the start of Great Expectations (the source for one of David Lean’s best films in 1946) is motivated by fear, as far as Pip is concerned; by original sin, in the eyes of his married sister; and remembered by Magwitch as an act of human kindness.

War and death, love and sex are bound to appear differently to children, and in retrospect to adult directors. Hope and Glory exploits the boy’s observations of his older sister’s love-making with a certain degree of prurience: the child’s voyeurism is less for his benefit, we feel, than for that of the adult audience. There is no shortage of films where the child’s eyes are borrowed to similar ends, to probe adult sexual and sentimental feelings.

The collision between the adult and child world can be comic, in films like Vice Versa, where father and son magically swop bodies, or Home Alone where the child is left to deal (more effectively) with an adult situation, or Kindergarten Cop, or Look Who’s Talking. Hollywood children tend to follow the example of The Kid rather than the kid of Zero de conduite: their ideal is the nuclear family and their problems are seldom political, more social and domestic. From Richard Fleischer’s Child of Divorce (1946) onwards, American cinema has been primarily concerned with exploring the psychology of the individual, sometimes succeeding, as in Rob Reiner’s Stand By Me (1986), in magically recapturing the specificity of a child’s outlook on the world.

Perhaps, if we are to give children their due, we must acknowledge the validity, on its own terms, of their interpretation of their surroundings, however differently adults may perceive things. Graham Greene’s story, The Basement Room, filmed in 1948 by Carol Reed as The Fallen Idol, is about a lonely boy befriended by the family manservant who tells lies to the police in the hope of protecting the man from suspicion of murder. The child here, like those in Bryan Forbes’s Whistle Down the Wind (1961), may have a better understanding of people than a society that judges them on a rigid scale of prejudices.

“In one sense,” Truffaut wrote, “Zero de conduite represents something rarer than [Vigo’s only other feature film] L’Atalante, because masterpieces devoted to childhood in literature or cinema can be counted on the fingers of one hand. They move us doubly since the aesthetic emotion is compounded by a biographical, personal, intimate emotion . . .”

Eventually children grow up; and all films about them, however much they adopt the child’s viewpoint, are about adults in the making. This is not always a message that either children or adults wish to hear. There have been two versions of William Golding’s Lord of the Flies (by Peter Brook, 1963, and by Harry Hook, 1990), neither fully prepared to confront the religious and social dimensions of Golding’s fable; yet each tells us that, left to themselves, children would not - like those in War of the Buttons - discover their own fundamental goodness, but revert to savagery.

This is almost like the adult’s counter-claim to the accusation implicit in those victim-of-war films: given the chance, we are to understand, they would behave just as badly as we do. Is there something distinctive about childhood, apart from its (so far) innocence and its accusing gaze? Subject to bombardment from the adult mass media, children may be starting to lose that specifically children’s gaze and to see the world already in adult terms. And the pervasive influence of Zero de conduite may be waning, for much the same reason: part of a canon of films which could only be seen in art cinemas and cine-clubs, Vigo’s masterpeice is now available - too easily available perhaps - on television and video. Will it be watched with the same intensity? It is slightly reassuring to know that it can still assert its presence in The War of the Buttons, a film whose makers believe that it is sometimes necessary for adults to be seen as The Enemy.