The introduction of AI is exacerbating existing technical and structural vulnerabilities inherent in the modern, digital information environment and creating new ones that threat actors, both state and non-state, are exploiting to manipulate people’s individual and collective perceptions, emotions, and decision-making processes. From disparately managed social media and instant messaging platforms, to deepfakes and fake on-line personas and websites, to malicious chatbots, digital information and communications technologies (ICT) have enabled the creation and spread of false and highly targeted content at an unprecedented scope and scale, creating what some have described as an epistemic, post-truth crisis and putting individual and national security at risk. Private and public efforts, both domestically and internationally, to address these risks, through digital governance models and otherwise, are fractured, inconsistent, and carry the risk of disproportionally impinging on fundamental rights. Building on its prior work around on-line harms, TLS will deepen and expand its research into the ICT-enabled threats to cognitive security, offering practicable recommendations on how to mitigate these significant harms while preserving civil liberties.