What role did religious differences play in the iranian revolution and the iran-iraq war?

In 1958, the aarp was organized to promote

It can be inferred that the dramatic increase in defense spending by germany was the result of. (a) attempts by great britain to take german colonies. ( b) fear of a two-front war against france and russia (c) the need to put down a communist rebellion (d) a competition with the allies to produce atomic weapons

Was the civil war inevitable? could anything have been done through compromise to stop it, or did it have to happen?