Naturally, defense against attack is accepted as a reasonable justification. This list is referring to reasons why a group would initiate open warfare.
Note – These are NOT numbered in order of importance, just for convenience. I have separated the order by external (Meaning warfare against a rival government) and internal (Within a country), but these can easily crossover.
1) Threat to way of life. Many times, cultural change from ‘outside’ is blamed for changing the way of life and the values of a society. Nationalism may be viewed as a contributing force here.
2) Economic gain. An opportunity to seize what is not yours through armed force.
3) Distraction. Blaming internal problems on external enemies.
1) Disagreement over form of government – Autocratic, socialist or democracy
2)Loyalty to organization other than the recognized government. (Loyalty to state over federal government, loyalty to clan or family over government, etc.)
3) Persecution and/or discrimination. (Race, Religion, clan, etc.)
4) Economic system. Capitalism, socialism. Spread the wealth or allow individuals to determine the direction of investment. Resources are the issues in many private arguments. In the public area, many times resources are at the heart of the issues for organized violence.