Rating: 4.25/5 
The story brings together Juliette (Donzelli) and Roméo (Jérémie Elkaïm), and, yes, they do comment on it. In a whirlwind sequence, the two meet, fall in love and soon there is a child on the way. They are young and overjoyed with their place in life, seeing the imminent arrival of their son as a splendid expression of their connection. This is life as they wish it to be.
When the boy is born, the family quickly settles into a routine familiar to any number of new parents, right up to the sleepless nights as infant Adam cries at all hours. They seek out support from doctors and other experts, originally receiving assurances that these are normal issues, but as additional problems mount – late developing motor skills, some upsetting facial swelling – it becomes terribly clear that there’s something else wrong. Further testing determines that Adam has a brain tumor and the couple is plunged into the relentless gloom of treatments, surgeries and a life spent in the dulled hallways of hospitals, trying to save the life of a boy too young to understand the tragedy that hangs over him.
Donzelli and Elkaïm are jointly credited with writing the screenplay, and it’s said to be highly autobiographical. The film certainly rings with the authenticity of a story that’s been lived as much as crafted. Anguish surrounding the well-being of a child is often used in films as a shortcut to establishing high drama, but Donzelli is clearly interested in the accumulated details of lives disrupted by the unthinkable. With probing accuracy, the film digs into the long trudge the central characters must undertake. There is no saturated nobility to their experience, no transplanted heroism to their endurance, mustered anew each day. It is a clear, ongoing challenge and Donzelli clasps hard on to the day-to-day of it all, providing as clear a sense as possible of what it must be like to put on sterile scrubs every day to visit a child stuck in a hospital crib.
It is heavy stuff, to be sure, but Donzelli unlocks the emotions of the piece by refusing to pander to the empathy of the audience. Instead, she directs the film with lively inventiveness. Like the earlier French New Wave films, Declaration of War employs overt narrative techniques in a manner intended to call attention to them rather than try to keep them hidden within the flow of the narrative. Donzelli is playful with the editing, the rhythm, the voiceover narration and, in the film’s most strikingly different moment, she inserts a musical number as Juliette and Roméo sing together from different locations, united through the movie magic of double exposure. There’s even an adoringly ironic iris-in shot right out of the Jules and Jim playbook. In less delicate hands, this could easily seem contrived, undercutting the weight of the story. Here it has the opposite effect; it conveys the terrible fullness of the experience, the film racing through a multitude of scenarios just as any distraught parent is likely to consider every theoretical option at their disposal to aid their child.
Maybe more than anything else, Declaration of War is about the enveloping experience of living with a child beset by illness. Any time Juliette and Roméo make a stab at normalcy, there is always a reminder that their lives are now anything but. They can’t cross the room at a party without someone coming up to express their sympathy or otherwise commiserate about the heartbreak they’re trying to set aside, if only momentarily. The emotional tenor of Donzelli’s film is perfect and achingly true, testifying to the fortitude it takes to live with such pain while also acknowledging the toll it exacts. In the end, the film shows how people can be utterly destroyed and yet still strong.
