At one point or another, hasn’t everyone wondered whether we’ll someday be thrown into the midst of a “World War III?” That’s exactly what happens in How I Live Now (2013), but the details of the war are never revealed. Who is fighting who? How did it start? Why couldn’t it be prevented? These are questions that pop up, but none of which are answered, which renders the underlying message of raw visceral emotion even more powerful.

It’s clear something is going to happen from the start. Daisy (Saoirse Ronan) arrives in London to a military-occupied airport. Her aunt, who has some form of unidentified government job with high security clearance, has spreadsheets of projected death tolls on her computer screen. That same aunt disappears to Geneva for peace talks, never to be seen again.

Then there’s a nuclear blast. Everything goes white. And the terror of human civilization outside the confines of government regulation kicks in.

How I Live Now is adapted from a young adult novel by Meg Rosoff, published in 2004. That fact is an important one; as much as How I Live Now is a post-apocalyptic tale of survival, it’s ultimately a love story, and a tale about human nature and its response to tragedy. To that end, ambiguity about the nature of the war is an effective plot device. It changes the formula of the film from one about politics and governments to one about humans. It shows the consequences of war on a personal level, and it reveals how war is devastating to the human condition. The scarcity of real information adds to the anxiety.

Franz Lustig, the film’s cinematographer, told Coming Soon, “If you want to show this world, you can just have it in the background. I think it enhances the world.”

Daisy finds the war to be a time of clarity, where she’s discovering purpose for the first time in her teenage life. War can debase human nature, but Daisy is pulling through it with the opposite outlook. Sure, she still has a lot of selfish tendencies and moments. The way she yells at Piper (Harley Bird) and threatens to leave her in the woods is cruel - almost as cruel as one would expect a teenager in the apocalypse to be.

“The movie is wise to focus tightly on Daisy and her cousins, without explaining the larger events. But this approach leaves a nagging question: Why would British troops brutalize kids who are neither outsiders nor insurgents? How I Live Now doesn't say. It's better at conveying raw emotions and intense sensations, translating the interior turmoil of adolescence into real-world combat.” - Mark Jenkins, NPR

No matter how, why, when, or where war breaks out, the consequences are the same. Identifying the enemy isn’t important. Examining the results, the destructive impact of war, is really what the film is about.