Civil defense -- United States

Homeland defense
Homeland security
nne United States Air defenses, Civil
nne United States Civil defense

H.R. 1292 (107th Congress, 1st session) (Sec. 6 Homeland Security Defined. In this Act, the term "homeland security" means the protection of the territory, critical infrastructures, and citizens of the United States by Federal, State, and local government entities from the threat or use of chemical, biological, radiological, nuclear, cyber, or conventional weapons by military or other means.)
WWW, June 28, 2002 (homeland security, homeland defense)