Are We on the Verge of Another Civil War?” So asks The Nation, in a headline for an interview with David Armitage, the Harvard historian and author of the recent book, Civil Wars: A History in Ideas (Knopf, 2017). “Are We Nearing Civil War?” So asks the American Conservative, in a headline for a column by Patrick J. Buchanan, the several times presidential candidate and former speechwriter for Richard Nixon. Across the political spectrum, from left to right and in the center, too, the question is anxiously posed: whether familiar and longstanding trends like partisan polarization and raucous civic discourse are inexorably leading to a new and more dangerous phase of the confrontation—an actual civil war. Indeed, some analysts say we have already entered the stage of civil war. “American society has divided along unreconcilable visions of the good, held by countrymen who increasingly regard each other as enemies,” Angelo M. Codevilla declared in “The Cold Civil War,” an essay published this spring in the Claremont Review of Books.