The American West is a region that has been conscripted into the service of the nation’s frontier myth. Nowhere are the absurdities and tragedies of this myth more apparent than in the U.S.-Mexico borderlands. From the hackneyed re-enactments of Tombstone’s Gunfight at the OK Corral to the real-life vigilantes and outlaws who haunt the deserts along the borderline, the violence of the frontier is alive in the borderlands in a way that feels simultaneously anachronistic and immediate.

New York University historian Greg Grandin explores this strange affinity between the frontier stockade and the border wall in The End of The Myth: From the Frontier to the Border Wall in the Mind of America. The scope of Grandin’s frontier history extends far beyond the borderlands or even the American West, ranging from the genocidal Indian wars of the 13 colonies to recent interventions into the affairs of the Central American nations that former President Ronald Reagan was fond of referring to as our “southern frontier.”

Such violent expansion of territory and influence has long provided an outlet, Grandin argues, for fundamental tensions within the American body politic. Whether it’s the class antagonism that Andrew Jackson sought to appease by brutally opening new territory for settlement, or the sectional divisions that were sutured in the unifying white nationalism of the Spanish-American War, The End of the Myth suggests that expansionism served as a “safety valve,” releasing pressures produced by our most-profound social contradictions.

Grandin borrows this concept of the frontier from the best-known frontier historian of all: Frederick Jackson Turner. In his controversial 1893 essay, “The Significance of the Frontier in American History”—notorious today for celebrating settler colonialism and downplaying its violence—Turner imagined the frontier as a mobile site where the class tensions of the Old World were supplanted by an epic struggle between civilization and savagery. For Turner, the story of this struggle was the narrative of U.S. history, the source of the democratic and egalitarian nature of the “American character.” His essay ends on a note of marked anxiety as he ponders the exhaustion of “free land” in the West: “At the end of a hundred years of life under the Constitution, the frontier has gone, and with its going has closed the first period of American history.”

Grandin comes to a different conclusion: In the final chapter of his 21st century frontier thesis, provocatively titled “The Significance of the Wall in U.S. History,” he argues that it was not the fulfillment of Manifest Destiny, but rather the election of Donald Trump, that marked the end of an era. After decades of foreign policy failures, from the jungles of Vietnam to the deserts of Iraq, “the frontier is closed, the safety valve shut,” Grandin warns. “After centuries of fleeing forward across the blood meridian, all the things that expansion was supposed to preserve have been destroyed, and all the things it was meant to destroy have been preserved.”

Turner’s myth of an egalitarian frontier democracy always obscured the bloody reality of history. Grandin, however, argues that Turner’s story has met its definitive and inevitable end in the white-supremacist ideology made manifest in Trump’s obsession—the border wall. The U.S.-Mexico border has become “the negation of the frontier,” a “repository of the racism and brutality” that Turner’s notion of history and its representation of the “savage” on the other side of the frontier had sought to project beyond the nation.

By echoing Turner’s anxieties about what, in his later years, he called “a nation thrown back upon itself,” Grandin offers a stirring condemnation of Trump. Through his ambivalent embrace of Turner, however, Grandin also risks inadvertently revisiting some of Turner’s blind spots. Grandin takes “the mind of America” as his subject, but the voices that dominate his book are those of white Americans—the intended beneficiaries of frontier expansion. In an especially remarkable omission, the voices of Indigenous scholars—people who have a lot to say about frontier conquest and its consequences—are almost entirely absent.

Many Indigenous intellectuals are skeptical of claims that Trump and the ideology he represents are exceptional or new. As Sisseton Wahpeton Oyate scholar Kim TallBear put it in the week following Trump’s election, “This week I do not grieve anew. … As a Dakota, we have struggled post-apocalyptically for a century and a half.” Grandin, on the other hand, argues that the emergency engendered by the election of Trump marks an epochal shift that will finally force Americans to face the choice that frontier expansion once allowed us to evade: “barbarism or socialism.”

Grandin may be “a rash prophet” (to borrow a phrase from Turner) for arguing that our contemporary crisis signals “the end of the myth” that has for so long sanctioned the United States’ expansive violence. Nonetheless, Grandin paints a vivid picture of the troubling continuities between frontier expansion, border vigilantism and military action abroad. By illuminating the litany of emergencies that is the history of U.S. empire, Grandin’s history does vital work in the ongoing struggle to reject the myth of the democratic frontier.

Alex Trimble Young is a scholar of U.S. culture and transnational settler colonialism. He lives in Phoenix, Arizona, where he teaches at Barrett, the Honors College at Arizona State University. This piece originally appeared in High Country News.

The End of the Myth: From the Frontier to the Border Wall in the Mind of America

By Greg Grandin

Metropolitan Books

384 pages, $30