(1) Naturalist war scholars believe that the root of war lies in the natural environment and human biological nature, and war is a natural and eternal phenomenon.

(2) Religious war disputants believe that war is God's punishment for people, and use supernatural power to explain the causes of war.

(3) Racists believe that the cause of war is the difference between superior and inferior nations.

(4) Modern geopolitical scholars believe that war is based on geographical environment, that is, fighting for a certain living space and natural resources.

(5) Malthusians believe that overpopulation and hunger are the real causes of war.

(6) Historical materialism holds that war has never happened and is not eternal. War is the product of the development of social productive forces and relations of production to a certain stage, and it only appears after the emergence of private ownership, the formation of classes and countries, and oppression and oppression.

Generally speaking, the root of war is political, economic, social and cultural factors. Uneven distribution of resources/benefits and cultural/belief differences are the main reasons for the war.