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.

Organization

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 obvious benefit of any military is in providing protection from foreign armed forces, and from internal conflict. In recent decades standing armies have also been used as emergency civil support roles in post-disaster situations. On the other hand they may also harm a society by engaging in counter-productive (or merely unsuccessful) warfare, by domestic repression, or simply by supporting the idea that violence (or the threat thereof) is the way to get what one wants.

Military investment in science and technology has brought many side benefits, although some argue that greater benefits would come from targetting the money directly at wanted technologies and basic science.

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 society's ability to improve its infrastructure. This lack of development in turn affects the military in a vicious cycle. See the Soviet Union for a typical modern example of this problem.

Transarmament is a recent movement to replace armed forces with nonviolence training and infrastructure.

Armed forces of the world

Military of Afghanistan
Military of Albania
Military of Austria
Military of Belgium
Military of Canada
Military of China (PRC)
Military of Colombia
Military of Cuba
Military of Denmark
Military of France
Military of Finland
Military of Germany
Military of Honduras
Military of Hungary
Military of Indonesia
Military of Italy
Military of Israel
Military of Liechtenstein
Military of the Netherlands
Military of Norway
Military of Portugal
Military of Russia
Military of Saudi Arabia
Military of Serbia and Montenegro
Military of Singapore
Military of South Africa
Military of Spain
Military of Sudan
Military of Syria
Military of Sweden
Military of Switzerland
Military of Taiwan (ROC)
Military of Tajikistan
Military of Turkmenistan
Military of Turkey
Military of the United Arab Emirates
Military of the United Kingdom
Military of the United States
Military of Uzbekistan
Military of Yemen

See also: Military Science, Military History, Military Junta, Military tactics, Military technology and equipment and Military academy, Military incompetence, Military fiat, Military Aid to the Civil Power, Military Aid to the Civil Community