Which U.S. federal government agency is tasked with preventing terrorist attacks?

The Department of Homeland Security (DHS) is the federal agency specifically created to address and manage threats to national security, including the prevention of terrorist attacks. Established in response to the September 11, 2001 terrorist attacks, the DHS coordinates various federal initiatives and programs aimed at protecting the United States from terrorism. This includes a wide array of responsibilities, such as border security, emergency response, and intelligence gathering, making it crucial in the nation's efforts to prevent and respond to terrorist threats.

The other agencies listed have different primary missions. For instance, the Department of Defense focuses primarily on military operations and national defense, the Department of Transportation manages the nation’s transportation systems, and the Centers for Disease Control and Prevention is tasked with public health and safety regarding diseases and health threats, rather than direct counter-terrorism efforts. Thus, the DHS is uniquely positioned as the lead agency in the prevention of terrorist attacks.