In some ways this film is the platonic ideal of light cinematic entertainment. It's a balanced, polished, well-paced little thing, in which everything functions so adequately that it can't help being pleasant any more than it can avoid being dull. Despite being set in Nazi-occupied France, the film is marinated in the sort of golden-sunlight sentimentality that makes everything look correct and pretty. Even the occasional SS raid manages to look somewhat idyllic. This approachable war-torn setting provides a backdrop for the titular war, an ongoing turf battle between neighboring gangs of provincial 10- to 12-year-old boys, who push each other into lakes, spar with wooden swords, brandish pocketknives, and, most notably, de-button the garments of enemy "POWs" as a form of shaming.
The story is adapted from a novel written in 1912 as a piece of pacifist literature by a reluctant French soldier, and most of what is poignant and worthwhile about this film can be credited to the source content, which provides enough sincere commentary on war and human nature to weather even the most bland, pedestrian retelling. The decision to nest this narrative within the context of a larger, more "real" war is unique to this adaptation, however. The film uses the parallel narratives to draw lines between the behavior of the adults and that of the warring children, and goads the audience into speculating how much the former's concepts of militarism and nationalism influence growing strains of barbaric tendencies within the latter. The energy that the film dedicates to telling the adults' story (a burgeoning resistance movement led by unlikely characters in the town), which is given almost equal screen time, dilutes the edgier Lord of the Flies–ish elements with fairly hackneyed WWII tropes, but there's no denying that the two plots are woven together well and are thematically complementary. An easy movie to watch, but ultimately about as life-changing as a short nap.