With Shia dominated Iraq to the north and these Shia guerillas ousting the sunni government in Yemen to the South Saudi Arabia is certainly concerned. What the idiots in this administration do not understand is that actions have consequences. Do they actually think that if Iran gets a nuke that’s the end of it? Once they get a nuke anyone with half a brain knows that Saudi Arabia will be on the fast track to get one also. Who knows where this nuclear arms race would end.
So many people have pointed this out too. The Obama plan that allows a path to nuclear weapons for Iran is the worst outcome for the world that we could end up with. It would make every other idiotic policy and program seem like small potatoes by comparison.
An additional factor is that we have shown clearly that we will not abide by agreements such as the agreements (plural) with Ukraine that if they disposed of their nukes, we, Britain, etc., would come to Ukraine's aid. (Those agreements did not mean using them [Ukraine] as cannon fodder / pawns!)
The world has seen that the West cannot anymore be trusted in this regard -- if we now give Iran the capability to make ANY type nuclear weapon, it will be clear to countries all around the world, not just in the Middle East, that those countries will have to plan accordingly. IIRC, around 20 countries now lacking nuclear weapons are regarded as "nuclear capable". I suspect that figure may not include some that could, once the race was "on", acquire the weapons from others.
This almost certainly WILL lead to a significant nuclear war in the future. If we (the US) are lucky, we'll just catch the fallout.