I am a scholar of international security. For most of my life, I’ve been focused on threats like nuclear annihilation and “Great Power war”—conflict with China or Russia. But today, for the first time in my life, the most significant threat to our country comes from within. Since 9/11, there have been 107 deaths in the U.S. from jihadi violence—and 114 deaths from violence by right-wing domestic extremists, many of them white supremacists. But the numbers don’t represent the true nature of the threat.