text: Chapter 1
  between cause and effect challenging, and it contributes to the uncertain nature of war and human
  competition. This requires that commanders, supported by their staffs, develop and maintain the best possible
  understanding of their operational environment. Several tools and processes assist commanders and staffs in
  understanding their operational environment. They include—
  (cid:122) Domains.
  (cid:122) Dimensions.
  (cid:122) Operational and mission variables (detailed in FM 6-0).
  (cid:122) Running estimates (described in ADP 5-0).
  (cid:122) Army design methodology (described in ATP 5-0.1).
  (cid:122) The military decision-making process (described in ADP 5-0).
  (cid:122) Building intelligence knowledge (described in FM 2-0).
  (cid:122) Intelligence preparation of the battlefield (described in ATP 2-01.3).
  (cid:122) Sustainment preparation of the operational environment (described in FM 4-0).
  DOMAINS
  1-82. Within the context of an operational environment, a domain is a physically defined portion of an
  operational environment requiring a unique set of warfighting capabilities and skills. Each military
  Service and branch trains and educates its leaders to be experts about operations in a primary domain,
  although each Service has some capability in each of the domains, and each develops shared understanding
  of how to integrate capabilities from different domains. Land operations require mastery of terrain and ground
  maneuver. Cyberspace operations require mastery of digital information systems and computer code. Space,
  air, and maritime operations likewise require specific capabilities and skills, which manifest themselves in
  separate Services within the joint force. Although most domains align with the skills developed in a particular
  Service, no Service focuses entirely upon or exerts total control of that single domain during operations. Joint
  commanders assign responsibilities and task-organize based on mission requirements. However, the domains
  present very different conditions of warfare and require the specialized warfighting skills developed by the
  different Services and subcomponents within each of the
  Services. Army leaders do not need to understand all the Understanding the strengths and
  technical components of what the joint force does in other dependencies of joint capabilities in
  each domain is fundamental to a
  domains, but they do need to understand the complementary
  multidomain, combined arms approach
  and reinforcing ways in which they can request and employ
  to operations.
  those capabilities and methods in support of operations on
  land. (See Chapter 3 for a discussion of convergence.)
  Land Domain
  1-83. The land domain is the area of the Earth’s surface ending at the high water mark and overlapping with
  the maritime domain in the landward segment of the littorals (JP 3-31). Variations in climate, terrain, and the
  diversity of populations have a far greater impact on operations in the land domain than in any other domain.
  The most distinguishing characteristic of the land domain is the human dimension. Humans transit the
  maritime, air, and space domains, but they ultimately live, make political decisions, and seek conflict
  resolution on land.
  1-84. The nature of combat on land is unique due to the impacts of terrain on all warfighting functions and
  the application of combat power. For example, terrain provides forces opportunities for evading detection
  and increasing survivability. It also provides enemy forces the same opportunities. Although technology
  increases the range of capabilities, complex terrain causes opposing forces to fight at close ranges. Land
  combatants routinely come face-to-face with one another in large numbers in a wide variety of operational
  environments containing all types of terrain and potentially nuclear, biological, and chemically degraded
  environments. When other means fail to drive enemy forces from their positions, Army forces close with and
  destroy or capture them through close combat. Close combat is warfare carried out on land in a direct-fire
  fight, supported by direct and indirect fires and other assets (ADP 3-0). The outcome of battles and
  engagements depends on the ability of Army forces to close with enemy forces and prevail in close combat.