Saudi will do exactly what we want them to do so long as it is done outside of the public view, saving face is very important in the Middle East.
Saidi is scared Sh—less of Iran and with good cause. If one looks at the population of Iran and Saudi and the ability to put great numbers of men in combat, Iran wins. If Iran becomes nuclear it is game over unless Saudi is also nuclear or defended by our military and its nuclear ability.
Without our military support and access to our military weapons they would cease to exist and that is not good for Saudi nor the USA.
As an aside I must comment that oil prices today are just right. At the present price shale oil fracking is very commercial and our production rates increase month by month.
The Saudis tried to kill our shale oil fields some years ago by producing huge amounts of oil and driving the price down. This did bankrupt many but that oil was still in the ground.
We came back leaner and meaner and now produce record amounts of oil at much lower production costs. Those leases that went bankrupt were bought at a bargain price and are now being drilled and producing. Capitalism works!
Saudi has state capitalism and thus failed in their efforts to kill shale oil in the USA. A state directed effort can never compete with free capitalism.
The day the Saudis drop the petro-dollar will be a game changer for the US economy.
Something that *could* take years (decades?) to recover from.