Combined arms

Combined arms is an approach to warfare which seeks to integrate different combat arms of a military to achieve mutually complementary effects (for example, using infantry and armor in an urban environment, where one supports the other, or both support each other). According to strategist William S. Lind, combined arms can be distinguished from the concept of "supporting arms" as follows:

Combined arms hits the enemy with two or more arms simultaneously in such a manner that the actions he must take to defend himself from one make him more vulnerable to another. In contrast, supporting arms is hitting the enemy with two or more arms in sequence, or if simultaneously, then in such combination that the actions the enemy must take to defend himself from one also defends himself from the other(s).

Though the lower- units of a combined arms team may be of similar 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, reconnaissance, and perhaps even helicopter units, all coordinated and directed by a unified command structure.

Also, most modern military units can, if the situation requires it, call on yet more branches of the military, such as fighter or bomber aircraft or naval forces, to support their operations. 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 operations dates back to antiquity, where armies would usually field a screen of skirmishers to protect their spearmen during the approach to contact. Especially in the case of the Greek hoplites, however, the focus of military thinking lay almost exclusively on the heavy infantry. In more elaborate situations armies of various nationalities fielded different combinations of light, medium, or heavy infantry, cavalry, chariotry, camelry, elephantry, and artillery (mechanical weapons); the ancient Persian army is an excellent example of this. Combined arms in this context was how to best use the cooperating units, variously armed with side-arms, spears, or missile weapons in order to coordinate an attack to disrupt and then destroy the enemy.

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