They have the third largest oil reserves in the world. The nationalization of their entire oil industry was what caused the U.S. and Britain to intervene in the first place, to engineer a coup and install the Shah, whose stupid brutalities eventually caused the revolution and the rise of folks like Khomeini and Ahmadinejad and now Rouhani.
It can be oversimplified, but when people say "it's all about oil" there's a lot of truth to it.
All that is needed to make a happy life is within yourself, in your way of thinking. -Marcus Aurelius