Fake news, hoaxes, conspiracy theories, rumors? Disinformation would appear to be everywhere, and the truth nowhere to be found. These questions preoccupy our societies, in which the Internet seemingly allows everyone to express themselves. However, disinformation has a history. It expressed itself during the Cold War and accompanied globalization, even before the web and social networks provided it with new possibilities. As we explore the mechanisms of the phenomena that take advantage of us, systems of power emerge, and new forms of ideologies manifest themselves. When the truthfulness of facts becomes the central object of our struggles, disinformation is no longer just a moral question: it is a strategic issue.