The critical mission of defending the U.S. homeland—homeland defense—requires a fully integrated capability to identify, categorize, and fuse strategic and tactical indications and warnings (I&W) by U.S. Strategic Command (USSTRATCOM), North American Aerospace Defense Command (NORAD), U.S. Northern Command (USNORTHCOM), and U.S. Pacific Command (USPACOM). 

Cyberspace is frequently referred to as the fifth domain, alluding to its perceived role as the next major battlefield after land, sea, air, and space.

Blackouts. School testing. Electrical grids. Insurance. These all have one major thing in common: they have all been targets for cyber attacks in a period of two weeks during March 2015. The United States faces thousands of cyber assaults every day