An example of: 3. Sectionalism
So, to find out what IS a cause of the war we need to know M.A.I.N. That means Militarism, alliances, imperialism, and nationalism. That would mean the choices that aren't causes are totalitarianism, defense, and industrialism.
Becasue they had nothing better to do
I believe one was the middle east
The answer is wealth was concentrated in the hands of few.
