Roo, you can't be serious - we supported a king similar to the Saudis for decades in order to maintain a similar level of control there as to the gulf, then engaged in a variety of hostile avts when the Iranians deposed him - including bombing Iran and blockading the country, arming its enemy and sponsoring an invasion (Iran Iraq remember?), and only now are nukes an issue...as if the constant warfare should not weigh in on the Iranian policy makers.
Israel's support for the Shah was motivated by the same reason for Israel's continued belligerence - control of the oil producing states is central to US policy in the region and consequently Israeli security and wealth. It's a lot easier to get resources and support from puppets like the Saudis and Mubarakmthan from regimes that aren't dependent on the US.
Support for the Shah was based on those policies that continue to make the US and Israel a threat, it was not the cause of the problem.
And the obvious fact is that, if Iran has nukes, those options are off the table, and the US has to negotiate with them like it does the Pakistanis, north Koreans, and lots of other regimes it would rather sanction and attack like it did to Saddam.