Why is fear the main cause of war? Need at least 3 to 4 examples on why it is?

1) when peopple are scared they do not think rationally. 2) fear can cause war because they might believe their is no other solutions. 3) Fear can cause a war, because peopple naturally have an instict to predict them selves if faced with fear etc. 4) people not being able to control their emotions , such as ffear cause wars.