When the apocalypse happens, all that’s going to be left for us are the guns. This is the subtext of the dystopian young adult film “The 5th Wave.” The film opens with a winsome teenaged blonde executing a man with a military-style assault rifle, and the gunplay only goes further from there.

There’s a deeply anti-government streak to the politics of “The 5th Wave,” which imagines a world in which an alien race takes over the planet and starts eradicating the human species in a series of waves that destroy infrastructure, environment and health. The panicked surviving humans band together in the woods until their children are rounded up by the army for “protection.” Cassie (Chloë Grace Moretz) escapes the collection and ends up alone in the woods with only a few guns for comfort. She sets out to find her little brother, Sam, ostensibly to return his stuffed bear.

Perhaps the reason why some of the themes and imagery hit a bit too close is the way the film creates a recognizable world. In young adult hits of the same genre (“The Hunger Games,” “Divergent” or “The Maze Runner”), the metaphor has a bit more freedom because the worlds in which they take place are visually fantastical and removed from our reality. Everything in “The 5th Wave” feels, or at least looks, real.

This could be an opportunity for a subversive and satirical text, and at times, “The 5th Wave” comes close to feeling like Paul Verhoeven’s great propaganda parody “Starship Troopers,” particularly in the scenes of the young kids suiting up for battle — a small girl in full tactical gear and a long rifle is just funny (or is it?). But this film is sorely lacking in irony; if there is any camp or humor to be found (and there is some), it’s mostly unintentional.

There’s your expected love triangle, with hunky loner lumberjack Evan Walker (Alex Roe) positioned against high school crush Ben Parish (Nick Robinson). The execution of said triangle is generically laughable. Expository speeches are the technique of choice for writers Susannah Grant, Akiva Goldsman and Jeff Pinkner, who adapted Rick Yancey’s novel. Not only does Cassie have a voice-over to explain things, but characters dump information in rapid-fire speeches filled with revelations of machinations that they’ve put together awfully quickly. The twists and turns of the plot are telegraphed from miles away, so there’s not an ounce of suspense.

The filmmaking itself (the film is directed by J Blakeson) is aesthetically pleasing enough, and the story clips along at a fair pace. Moretz is a charismatic actor, but her performance here is standard-issue. Maria Bello relishes a chance to chew scenery as one of the manipulative Army sergeants, while Liev Schreiber phones it in for a paycheck as the colonel. On the surface, “The 5th Wave” is mindlessly silly enough, but has a weirdly virulent pro-gun, libertarian streak just under the surface. But really, haven’t teens always been the true libertarians?