In addition to a long and rich history, the subject of war has also undergone numerous analytical processes throughout the ages. Much of the research that has taken place after World War II concentrated on the causes, conduct, and prevention of war. These theories influence human behaviour and expectations, and the various schools of theorists recognize the importance of these ideas. However, it is crucial to note that a theory of war does not necessarily reflect the views of the masses; it can sometimes be a self-fulfilling prophecy.

A philosophical analysis of war will generally focus on four questions, including the nature of war, the relation between humans and their environment, and the moral justification of war. A general definition of war must be determined, including the entities allowed to engage in it. A political philosophy may also have a role to play in the definition of war, as an alternative definition may reflect an author’s philosophical or political stance. For example, a conflict between two schools of thought can be defined as war.

The combined armed forces of all nations contain around 21.3 million men. The largest, and most powerful, military is the United States, followed by China. Other large countries include India, North Korea, and Russia. However, the largest proportion of militaries are located in developing nations. In 2003, there were at least 30 active wars in 30 countries, including Afghanistan, Algeria, and Congo. A recent report shows that a quarter of all wars are fought by men.

While a strong emphasis on man’s choices as the causes of war is a compelling one, it can be misleading to view the underlying cause of war as primarily a product of human nature. The focus on man’s political, ethical, and biological qualities, as well as the structure of social relations and institutions, fails to account for the more complex and nuanced nature of war. For example, a strong emphasis on reason as the cause of war ignores cultural, biological, and rational factors.