Nationalism and historical memory are as inseparable in modern history as air and breathing. In his 1961 masterwork, The Legacy of the Civil War, Robert Penn Warren succinctly and lyrically described the place of the war in the nation’s memory: “The Civil War draws us as an oracle darkly unriddled and portentous, of national as well as personal fate.” This connection of the personal to the national, of individual and family memory to the country’s contending narratives of the Civil War, has infused the American imagination through one anniversary after another, up to the 150th this year.

In his recent book, The Legacy of the Second World War (2010), the historian John Lukacs ponders why, 65 years on, the conflagration of 1939–45 continues to stimulate the world’s imagination and shape attitudes toward geopolitics. He muses on several possible answers: fascination with historical drama on such a grand scale, with the horrible or with man’s capacity for “evil”, and with the enduring sense that the “structure of international history” had forever been changed. Lukacs also reflects on how and why many in the West, in the victor nations, at least, have reified World War II into the model “good war”, and he is, moreover, intrigued to know how a war for or against aggressive ideologies captured in the large abstract categories of fascism, communism and democracy left such powerful legacies in our subsequent debates over the place of ideas in history.

As any student of World War II must, Lukacs also seeks the roots of the Cold War in the consequences of 1945—and there are a multitude of legacies to be found and debated, perhaps forever. As a scholar of historical consciousness, Lukacs further believes the magnitude and stakes of that war gave historians and readers many fruitful ways to ask fundamental questions about just what in history may or may not be truly “inevitable.” However, Lukacs is most lastingly interested not only in how an unprecedentedly destructive war between nationalisms failed to banish such an impulse, but also how it can be that, well into the 21st century, “the essence of history is the nation” and that nationalism itself remains the “principal political factor” driving global events.

As we experience the sesquicentennial of the American Civil War, Lukacs’s musings on the meaning and legacies of World War II are a useful way of thinking about the place of America’s greatest crisis in our national memory. How Americans have processed and fought over the meaning and memory of the Civil War has long been an index of who we believe we are as a people and a nation. In broad terms, disunion, all-out civil war, a struggle of conquest and...