Joanna Scutts, a literary critic and cultural historian, is the author of “The Extra Woman: How Marjorie Hillis Led a Generation of Women to Live Alone and Like It.”

World War I fundamentally reshaped America’s sense of itself and its relation to the world; it also helped form our modern understanding of citizenship, democracy and the role of the state. But in the American popular imagination, the war is a blank, a situation without a story. President Trump’s decision not to attend a wreath-laying at the Aisne-Marne cemetery on the 100th anniversary of the armistice may have met with fierce criticism, but it’s undeniable that the centenary passed in the United States with far less ceremony or public reckoning than in the other combatant nations. Now that this landmark has come and gone, World War I is poised to recede again into its vague mist of sacrifice and service, a European fight that matters only as the prelude to World War II.

The story traces America’s journey from geopolitical isolation to engagement and back to a more committed isolation — a retrenchment that, like Woodrow Wilson, Peck considers a mistake (although he makes that case only tentatively). Along the way, Peck shares plenty of details worthy of their own histories: the tale of Herbert Hoover’s extraordinary relief efforts on behalf of Belgian refugees; the German sabotage of the munitions depot at Black Tom Island in New Jersey, which shattered windows in Brooklyn and damaged the Statue of Liberty; and the Anti-Saloon League’s campaign to capitalize on wartime anti-German (and hence anti-brewer) prejudice to shove through its fundamentalist version of Prohibition. But amid a parade of other facts, these details too often feel included but not incorporated, their significance hard to judge. The overall sense is of the war as a mass of coincidence rather than one with clear causations.

Peck is a member of the advisory council of the Woodrow Wilson House in Washington, and he takes pains to clarify that his book is neither a biography of Wilson nor a defense of the man’s politics and policies. But as any historian of America in World War I well knows, neutrality is a difficult and delicate balance to hold. In his introduction, Peck describes how a Facebook friend “chimed in dismissively” on his project with the judgment that Wilson was “a bigot and a racist,” a comment that Peck calls “playing the race card” — a dismissal of its own and a much less forgivable one.

Wilson’s racism was far from unique for his time. But to present it as a character flaw and not a worldview prevents an honest reckoning with his legacy as a whole, including the parts that Peck admires: his idealism and his commitment to peace and a world “made safe for democracy.” Peck quotes Wilson, in early 1917, telling his private adviser Edward House, “We are the only one of the great white nations that is free from war today, and it would be a crime against civilization for us to go in,” and a few pages later warning his Cabinet that “getting involved in the war would weaken the white race, in particular against the ‘yellow race’ like the Japanese” — but he merely calls this latter statement of Wilson’s “rather surprising.”

It is no more surprising than Wilson’s refusal to meet with William Monroe Trotter, a black civil rights activist, after giving what Peck calls Wilson’s “Gettysburg Address” at the Suresnes military cemetery in May 1919. It is the historian’s responsibility to connect these dots, to interrogate what “civilization” and “peace” mean to a man for whom “greatness” and “whiteness” are so self-evidently intertwined.

Domestically, World War I represented a prolonged test of what constituted American citizenship and patriotic loyalty, and the country’s entry on the side of the Allies was by no means certain. German Americans were the largest ethnic group in the United States before the war, and Irish Americans were likewise no supporters of the British. The specter of divided loyalties loomed over American attitudes toward the war, leading Teddy Roosevelt to denounce what he called “hyphenates,” those whose ethnic identities made them unreliable citizen-subjects. Wilson later adopted the same rhetoric, exposing the vicious undercurrent of the assimilation sunnily encouraged in wartime propaganda, which presented military service as a way of erasing one’s troublesome ethnic origins and becoming securely American.

World War I saw Americans struggling more profoundly than at any time since the Civil War with the question of who they were — and who they were not. That struggle reverberated in numerous arenas, including the victorious fight for women’s suffrage. But it also spurred a crackdown on dissent that targeted German Americans, labor organizers, radicals and socialists, many of them Jewish, and that vastly expanded the state’s power over the lives of its citizens. It helped drive the resurgence of the Ku Klux Klan and the vicious racial violence that flared nationwide as African American servicemen returned home.

The battle to define American-ness in expansive and inclusive terms is as urgent now as it was a century ago. It deserves to be central to any analysis of what World War I means, then and now, to a country that prefers not to think about it.


World War I and its Aftermath

By Garrett Peck

Pegasus. 432 pp. $29.95