The year is 2022, and America is “a nation reborn.” Unemployment is at 1 percent, and the crime rate is at a record low — all thanks to the New Founding Fathers, who have sanctioned a 12-hour period each year for society to purge itself of its pent-up violent aggression. This “countrywide catharsis” operates under the Hobbesian notion that humans are inherently self-interested beings who will continually seek to eradicate competition in support of their own self-preservation. To address this condition, which had plagued the United States with rampant crime, the government allows its citizens a relief every year to self-regulate. All emergency services are suspended during this period, and Americans are free to steal, rape and kill with impunity.

James DeMonaco’s dystopian thriller “The Purge” focuses on the Sandin family as they struggle to get through this annual epidemic of violence. James Sandin (Ethan Hawke) is a security system salesman who plans to survive the night by locking his family into their suburban fortress. Trouble arises, however, when his son, Charlie (Max Burkholder), disarms the system to let in a bloody stranger (Edwin Hodge) on the run from a group of masked murderers. When the stranger’s pursuers come knocking on their door, Sandin and his wife, Mary (Lena Headey), find themselves caught between the need to survive and protect their family and the moral implications of participating in “the purge.” The leader of the masked group, played by a chillingly sinister Rhys Wakefield, gives the Sandins a gruesome ultimatum: Either they release the stranger — who, as a lower-class member of society, will be brutally executed — or their home will be invaded and the whole family will be killed.

This thought-provoking premise gives “The Purge” the opportunity to examine the ethical and political responsibilities of the state and to explore how these two elements are at some times interwoven, while at other times appearing completely separate. Media outlets in the film voice arguments for and against the necessity of “the purge,” with some pointing to its effectiveness in reducing crime and others challenging it as a way for the rich to unburden the economy of society’s noncontributing members. DeMonaco clearly anticipates the implausibility of the scenario and subsequently weaves in elements of social critique that justify the film as a philosophical ponderance rather than a believable futuristic situation. His villains are highly educated, well-mannered, upper-crust young adults who argue that their socioeconomic status entitles them to purge and kill off the homeless. His protagonists, however, come from the same stock but do not feel the need to purge themselves or their society. The film never comes to a clear conclusion regarding the morality of “the purge” and instead utilizes this ethical ambiguity as a platform to launch deeper questions concerning class conflict and the role of compassion in American society and government.

“The Purge,” although unique in its execution (no pun intended), is just one in a long list of films, from Christopher Nolan’s “Batman” trilogy to “The Hunger Games,” that caters to America’s fascination with dystopian near-futures. Unlike more reputable films of its genre, however, “The Purge” falls right into its own trap by predictably indulging in a violent bloodbath in the third act. This descent into the very behavior it calls into question lessens the intellectual impact of the film while at the same time making it more engaging as a thriller. Despite its promising start and value-challenging premise, “The Purge” is a film that makes a very strong but disappointingly short-lived impression.