Humane: How the United States Abandoned Peace and Reinvented War

In the years since 9/11, we have entered an age of endless war, with the United States exercising dominion everywhere. In Humane, Samuel Moyn asks a troubling but urgent question: What if efforts to make war more ethical—to ban torture and limit civilian casualties—have only shored up the military enterprise and made it sturdier?

To advance this case, Moyn looks back at a century and a half of passionate arguments about the...