According to the National Preparedness Goal, one of the core capabilities identified are the prevention of threats involving acts of terrorism. One of the greatest threats the Nation continues to face is the possible use of Improvised Nuclear Devices $($IND$)$ by terrorists. What development and sustaining actions have been employed to counter the possibility of a nuclear terrorist incident using INDs within the United States? Discuss how the Department of Homeland Security $($DHS$),$ the Department of Defense $($DoD$),$ and Department of Energy National Nuclear Security Agency $($DoE NNSA$)$ work together in a mutually supporting role of developing and sustaining core capabilities that thwart the use of INDs by terrorist organizations.