Marche has made a real contribution by endeavoring to fill in the details for possible futures that remain, for most of us, the creatures of wee-hour anxieties and feverish imaginations. Yet the scenarios he offers are not always convincing. I don’t know how the next civil war, should it come, will begin, but I highly doubt it will be precipitated by “agents” of the Federal Highway Administration. As the militia standoff escalates at the bridge, Marche relates, there are “torchlit rallies” and banners with swastikas and chants like “You will not replace us” and “Blood and soil.” We’re supposed to believe that all through this, the rebels maintain the support not only of locals but also of a wide swath of the nation. (Remember, President Donald Trump’s embrace of the far-right marchers in Charlottesville, Virginia, was widely rejected by the public and became an early and indelible stain on his presidency.) Why would a military response to the bridge standoff be necessary, given that the fictional encampment poses no immediate threat to life or limb? Would half the country really celebrate a presidential assassin as a “heroic resister,” or countenance the bombing of a Los Angeles synagogue? It would take both more and less than Marche anticipates to propel the United States into violent conflict. Oddly, he never contemplates the likeliest scenario, the one narrowly averted in 2020 and as likely as not to develop in 2024: a seriously disputed presidential election, with two pretenders to the throne.

Marche’s final chapter, on the possibility of a new state secession movement triggering the breakup of the United States, most clearly demonstrates the limits of his imaginative approach. While secession may be the “best-case scenario” for the United States, he argues, it is virtually impossible for it to happen. Why? Not because of Appomattox, or because the late Antonin Scalia once wrote a letter (often cited as if it were a binding opinion) stating that secession was unconstitutional. Rather, Marche leans heavily on his big discovery that a successful independence movement requires recognition from the United Nations Security Council, where the United States possesses a veto. Q.E.D.? Maybe, except that elsewhere in the book he notes that if the United States crumbles, “the peace and security of the global order falls.” For a book so richly imagined in some respects, Marche seems to expect that the secession of one or another state, or the dissolution of the Union in one fell swoop, would occur in a tidy vacuum, an otherwise orderly world. Far more likely it would be the consequence, not the cause, of a massive and potentially violent constitutional crisis—perhaps combined with other scenarios Marche explores, such as widespread environmental catastrophe and economic collapse. Should that be the case, why assume the already hapless U.N. remains intact?