The Foundation for Defense of Democracies (FDD) is a nonpartisan research institute and think tank based in Washington, D.C. Founded in 2001, shortly after the September 11 attacks, FDD focuses on national security and foreign policy. The organization is dedicated to promoting democratic values and combating ideologies that threaten democracy, particularly terrorism and militant Islamism.

FDD conducts in-depth research and analysis on various security issues, including nuclear non-proliferation, cyber threats, and geopolitical conflicts. It engages in investigative journalism to expose illicit activities and informs policy debates. The foundation also provides education through events and briefings aimed at public officials and the policy community. FDD houses specialized centers that focus on military, economic, and technological aspects of American power. Its work supports U.S. policymakers and the broader public in understanding and addressing national security challenges.