Warfare complements the four classical dimensions: land, sea, air, and space
The fifth dimension of warfare complements the four classical dimensions: land, sea, air, and space. It was enunciated in 1995 as information operations.[1]
This is part of core U.S. military doctrine, that recognizes at least five dimensions, or "domains of warfare" for which it is responsible:[2]
Land
Sea
Air
Space
Information
The origin of the concept of fifth dimension operations was a criticism that the "domain approach" reflected "a failure to think beyond the normal 'four' dimensions of threats, both domestic and international".[3][4]