A searing reflection on the broken promise of safety in America. When a naked, mentally ill white man with an AR-15 killed four young adults of color at a nearby Waffle House, Nashville-based physician and gun policy scholar Dr. Jonathan M. Metzl once again advocated for commonsense gun reform. But as he peeled back evidence surrounding the racially charged mass shooting, a shocking question Did the approach he championed have it all wrong? Long a leading expert at the forefront of a movement advocating for gun reform as a matter of public health, Dr. Metzl has been on constant media call in the aftermath of fatal shootings. But the 2018 Nashville killings led him on a path toward recognizing the limitations of biomedical frameworks for fully diagnosing or treating the impassioned complexities of American gun politics. Increasingly, as Dr. Metzl came to understand it, public health is a harder sell in a nation that fundamentally disagrees about what it means to be safe, healthy, or free. This brilliant, piercing analysis shows mass shootings as a symptom of our most unresolved national conflicts. What We've Become ultimately sets us on the path of alliance-forging, racial-reckoning, and political power-brokering we must take to put things right.