Hello and welcome back. This is WAR 1870–1949: How Empires Rise and Fall. Today’s episode is called After the Guns: The War That Stayed in the Mind. Because the deeper claim is simple and brutal: 1914–1918 doesn’t end. It mutates. It changes the nervous system, the language, the politics, the moral imagination. The armistice stops the artillery. It does not stop the war inside the people who had to live under it.

Let’s begin with one survivor coming home.

He steps off a train into a station that looks ordinary, almost boring, and it hits him like an insult. A man next to him complains about the delay, about the food, about the weather—small complaints, normal life—and the survivor feels something rise in his chest that isn’t anger exactly, more like vertigo. How can the world be this intact? How can the world be this casual? His body  ...