A couple titles to extract stories from include
Peace Was in Their Hearts: Conscientious Objectors in World War II by Richard Anderson.
American Mennonites and the Great War 1914-1918 by Gerlof D. Hofman
Mennonites, Amish, and the American Civil War by Lehman & Nolt.
A recent publication is Bearing Witness: Stories of Martyrdom and Costly Discipleship by Moore & Keiderling. This book includes selections from the ongoing “Bearing Witness Stories Project.” See their website at https://martyrstories.org/
This project is an ongoing effort to present stories, not only of martyrs, but of costly discipleship in various parts of the world today.