In 2015, Linus Hagström, a professor of political science at the Swedish Defence University, questioned the wisdom of Sweden joining NATO in a coauthored opinion piece. After its publication, some of his colleagues, especially those in the Swedish military, ostracized Hagström. Some even accused him of being a traitor, “running errands” for Russian propaganda, and called for him to be fired. So what actually happened to Hagström? Simply put, he committed heresy. In the national security policy community, some ideas become orthodoxies in which dissent against them is profane. For...