Combined arms is a military doctrine that calls for several distinct types of soldiers and/or weapon systems to be coordinated operationally and tactically in order to provide maximum flexibility and cooperation during military operations. Though the lower-echelon units of a combined arms team may be of homogeneous types, a balanced mixture of such units are combined into an effective higher-echelon unit, whether formally in a table of organization or informally in an ad hoc solution to a battlefield problem. For example an armored division -- the modern paragon of combined arms doctrine -- consists of a mixture of infantry, tank, artillery, reconnaisance, and perhaps even helicopter units, all coordinated and directed by a unified command structure. The mixing of arms is sometimes pushed down below the level where homogeneity ordinarily prevails, for example by temporarily attaching a tank company to an infantry battalion. Combined arms doctrine contrasts with segregated arms where each unit is composed of only one type of soldier or weapon system as to provide maximum cohesion and concentration of force in a given weapon.

Historical Background

The basic idea of combined arms operations dates back to antiquity, where armies would usually field a screen of skirmishers to protect their spearmen during the approach to contact. In more elaborate situations the armies of various nationalities fielded different combinations of light, medium, or heavy infantry, cavalry, chariotry, camelry, elephantry, and artillery (mechanical weapons), with the cooperating units variously armed with side-arms, spears, or missile weapons in order to coordinate an attack in time and space that would best disrupt and then destroy the enemy.

For example, the classical era Roman legion was notionally a unit of heavy infantrymen, but it was normally fielded with integral or attached skirmishers, and some legions even incorporated an small cavalry unit. The legion was sometimes also incorporated into a higher-echelon combined arms unit, e.g. in one period it was customary for a general to command two legions plus two similarly sized units of auxiliaries, lighter units useful as screens or for combat in rough terrain.

Modern Combined Arms Doctrine

Operational level combined arms operations in modern warfare proceeds by securing logistic paths first, and then using these paths to deliver damage. The first stage is to control space. From space, one then controls the sea and air. From the sea and air, one can control the land.

In U.S. doctrines, control of space is secured by outspending other countries, and diplomatic efforts to control antisatellite and antiballistic weapons. It is possible that the U.S. military covertly opposes inexpensive civilian access to space because it could permit a less-wealthy opponent to gain military access to space.

The U.S. controls oceans using naval warfare, especially using carrier-based aircraft and nuclear attack submarines to interdict undesired foreign naval and ship traffic.

The first stage of a campaign is an extended intelligence-gathering phase, at least several weeks long. This attempts to identify command and control nexus, the enemy's assets and order of battle, significant enemy personnel, their habits, radio traffic, telephone systems, cable traffic, decryption, etc. The U.S. uses significant space and human intelligence assets in this phase. There are satellites designed for multispectral imaging, and radio collection. The U.S. also has high-resolution radar mounted in aircraft, to detect land warfare assets and aircraft. These are crucial for maintinaing battlefield situational awareness.

In exercises, one of the most disruptive actions of simulated forces opposing a U.S. force was to substitute motocycle couriers for electronic communications. Another significantly disruptive activity was to move force assets and decoy forces. Relatively simple decoys are able to fool aircraft ground-search radars, and satellite scanning.

Because of range limitations of chemically-powered aircraft, modern air power is local. When the U.S. desires air superiority, it follows a standard plan. In peace-time, airmen train very hard, with realistic air combat training. In war, the U.S. first acquires a local base, or concentrates aicraft carriers. Next, enemy anti-aircraft defenses are systematically attacked. Anti-air defense attacks use stealth aircraft and precision-guided bombs and cruise missiles to damage control centers, search radars and air-defense missile systems. Next, command and control centers are systematically, persistently attacked to hinder formation and coordination of enemy forces. Unlike earlier doctrines, major airports are not intentionally damaged, because they provide logistics beachheads. Aircraft are still attacked at outlying military airports, however.

During the air war, psychological warfare efforts begin to reduce civilian and paramilitary resistance. An essential component of this activity is to minimize civilian casualties, and give reassurances of continued property rights. It is essential that troops be disciplined to prevent looting and rape, in order for the psychological warfare operations to succeed.

The next phase of the war is to infiltrate target-location soldiers, and begin to use helicopters and ground attack aircraft to destroy the enemy's land-warfare assets, such as command and control nexi, tanks and troop concentrations. The attacking aircraft of this phase are slower, less-agile aircraft. They would be in more danger if enemy air-defense assets had not first been removed.

The next phase is to begin a sweep of enemy territory using tanks, supported by troops mounted in armored personnel carriers, and air power. The goal of these forces is to destroy any remaining troop concentrations and pacify areas.

Once an area is pacified, and civil populations docile, achieving political goals is usually possible.