Combat arms (or fighting arms in non-American parlance) is a collective name in a system of administrative military reference to those troops within national armed forces which participate in direct tactical land combat. In general they include units that carry or employ a weapon system such as the infantry, cavalry, and artillery units. The use of multiple combat arms in mutually supporting ways is known as combined arms.
In some countries, notably the British Army, the artillery units are categorised as combat support. Some armies such as the United States Army, classify combat engineers as a combat arm also, while armoured troops constitute a combat arm in name although many have histories derived from cavalry units. This is also true for the combat aviation units in many armed forces throughout the world.
Artillery is included as a combat arm primarily based on the history of employing cannons in close combat, and later in the anti-tank role until the advent of anti-tank guided missiles. The inclusion of special forces in some armed forces as a separate combat arm is often doctrinal because the troops of special forces units are essentially specialized infantry, often with historical links to ordinary light infantry units.
In Commonwealth Countries the combat arms in the Army are:
- Combat Engineers
- Combat Aviation
- Field Air Defence
In the United States Army the following branches are considered Combat Arms (Per US Army Field Manual FM 3-90 Appendix A):
- Armor (including Armored Cavalry)
- Field Artillery
- Air Defense Artillery
- Army Aviation (e.g., Attack Helicopter and Air Cavalry units)
- Special Forces
- Engineers (only Combat Engineers, e.g., Land Mine Clearance and Route Clearance (Also done by construction engineers in combat heavy units)). See also sapper.
- Cyber (As of 2014)
Note that Aviation and Engineer branches have many different roles, as such these branches can be Combat Arms, Combat Support or Combat Service Support depending on function.
United States Marine Corps doctrine designates only Infantry forces as Combat Arms, with all other Ground Combat Element forces (Field Artillery, Assault Amphibian, Combat Engineer, Light Armored Reconnaissance, Reconnaissance, and Tank) considered Combat Support. (Air Defense, as a part of Marine Aviation, is contained within the Aviation Combat Element.)
- p.11, Sterling Rush
- p.333, Hofmann
- Through Mobility We Conquer: The Mechanization of U.S. Cavalry, University Press of Kentucky, 2006
- Sterling Rush, Robert, Enlisted Soldier's Guide, Stackpole Books, 2006