The Homeland Defense Institute (HDI) at the US Air Force Academy (USAFA) is a non-partisan, bi-national research institute promoting innovation, critical analysis, and collaboration on on modern homeland defense problems, challenges, and considerations. In close partnership with North American Aerospace Command, US Northern Command, the North American Defense and Security Academic Alliance (NADSAA) and the Institute for Future Conflict at USAFA, HDI provides analysis, research, and relevant education that impacts wide audiences and influences critical national security stakeholders. HDI's portfolio includes geographical issues (e.g., the Arctic, Canada, Mexico, and other close-in areas), functional challenges (e.g., missiles, old and new threats, offense-defense balance and national resilience), and existential threats.