White nationalism is a dangerous ideology that has seen an exponential rise in prevalence across the United States since 2017.1 The threat of white nationalism gained new attention after the insurrection on January 6 2021, where many members of the mob attacking the US Capitol displayed white nationalist symbols and slogans2. Other recent attacks motivated by white nationalist ideology include the shootings in a Walmart in El Paso, Texas; in mosques in Christchurch, New Zealand; in the Tree of Life Synagogue in Pittsburgh, Pennsylvania; and in the Emanuel African Methodist Episcopal Church in Charleston, South Carolina. White nationalist violence is not a new phenomenon, even if it is taking on new forms. In the United States, the 1979 Greensboro shootings, various attacks committed in the 1980s by “the Order,” and the 1995 Oklahoma City bombing, were all motivated by the white nationalist ideology.3 Increasingly, white nationalists are targeting young people for recruitment online, and white nationalism has been linked to bullying, threats, and violence in schools. For these reasons, it is critical that we all understand what white nationalism is and why it is harmful.