An Armed Force is formed for the defensive purpose of controlling territory
or other economic resources, and/or for the offensive purpose of seizing the
same from another entity.
The study of the use of Armed Forces is called Military Science. Broadly
speaking, this involves considering offense and defense at three "levels":
strategy, operative art, and tactics. All of these areas study the proper
application of the use of force in order to achieve a desired objective.
Armed forces may be organized as standing forces, which describes a
professional army that is engaged in no other profession than preparing for
and engaging in warfare. In contrast, there is the citizen army. A citizen
army (also known as a militia or reserve) is only formed as needed. Its
advantage lies in the fact that it is dramatically less expensive (in terms
of wealth, manpower, and opportunity cost) for the organizing society to
support. The disadvantage is that such a "citizen's army" is less well
trained and organized. Historically, professional armies often triumph over
much larger citizen armies when engaged in combat.
A compromise between the two has a small cadre of professional NCOs
(non-commissioned officers) and officers who act as a skeleton for a much
larger force. When war comes, this skeleton is filled out with conscripts or
reservists (former soldiers who volunteer for a small stipend to
occasionally train with the cadre to keep their military skills intact), who
form the wartime unit. This balances the pros and cons of each basic
organization, and allows the formation of huge armies (in terms of millions
of combatants), necessary in modern large scale warfare.
Militaries in many larger countries are divided into an army, an air force,
and a navy (if necessary). These divisions may be solely for the purposes of
training and support, or may be completely independent branches responsible
for conducting operations independently of other services. Most smaller
countries have a single military that encompasses all armed forces employed
by the country in question.
Benefits and Costs
The investment in military forces and their associated technologies can
result in many ancillary benefits to the society as a whole. While the
investment in a military is essentially consumptive (i.e. does not provide
direct benefit to a societies infrastructure or productive means), this does
not mean that these additional benefits have little value. These military
investments are increased during a war or other conflict, and in a virtuous
cycle can accelerate the technological development of the society as a whole.
Conversely, over investment in military forces can drain a society of needed
manpower and material, significantly impacting civilian living standards. If
continued over a significant period of time, this results in reduced
civilian research and development, degrading the overall societies ability
to improve its infrastructure. This lack of development in turn effects the
military in a vicious cycle. See the Soviet Union for a typical modern
example of this problem.
Militaries may also benefit their country by providing security from foreign
and internal conflict. They may also harm a society by engaging in
counter-productive (or merely unsuccessful) warfare, or by domestic repression.