War is an organized military conflict between two or more parties involving large-scale mobilization of armed forces and attempts to secure advantage over key trading routes, ethnic homelands, or major cities. While humans have been in conflict since the start, organized wars began only with the start of civilization.
Wars result when negotiations break down and armed conflict becomes the only way to settle scores. Below are the five reasons why bargaining breaks down, followed by four common causes of war.
Why Bargaining Breaks Down
Costs and benefits of war are seen differently by the two sides. Each thinks they can win cheaply.
Leaders have different incentives from the people. A war general might seek popularity even at great cost to his army.
Peace requires a broker (the Pope, the UN). When no such enforcer exists or is too weak, wars start.
Some resources cannot be divided. Jerusalem, a strait, a throne — only one power can hold it.
Outside parties enter the game and prevent arrangements due to their own fears and ambitions.
Common Causes of War
Tribes from less fertile lands attack more fertile ones. Japan needed Southeast Asia for raw materials its islands lacked.
When a fertile region has no natural barriers — no mountains, no rivers — there will be constant invasions.
Since the start of civilization, prosperity depended on trade. Major civilizations fought to control the key routes.
Wars start when a group feels its members are threatened by being part of another kingdom. In the past 3 centuries, ethnic fighting has become a major cause.
Now let's see how these causes played out across five contested regions over 4,000 years.
Five Theaters of War
Across all five theaters, the pattern repeats: flat, fertile land without natural barriers invites conquest. Empires rise, exhaust themselves, and fall — only to be replaced by the next power that sees the same prize. Geography doesn't change, so the wars keep coming.