Pakistan is the nuclear umbrella guarantor more than anything else.
I wouldn't exclude either a proliferation of bilateral nuclear sharing program in the world á la Russia-Belarus, especially in the Middle East.
Discussion
We have to remember though, that USA offered nuclear weapons to Saudi Arabia if they joined Israel against Iran. It was the Saudi king's old word that first Israel has to normalise relations with Palestine, that prevented the whole discussion, because the king's word is law...
Source of this offer from US?
I haven't read anything on it
Nothing about offering nuclear weapons I could find but a lot of talk about civilian nuclear technology.
https://www.armscontrol.org/act/2023-12/features/nuclear-mirage-us-nuclear-cooperation-saudi-arabia
Don't expect them to say directly that they will give nukes to Saudis against Iran. It would be like signaling Iran to acquire nukes as soon as possible. We have to ask why one of the biggest suppliers of energy on the planet would need nuclear energy for "the ever-evolving bargaining on regional security issues involving the U.S., Iran and Israel"
They work since a long time on diversifying their energy strategy. In my opinion the US wouldn't let the Saudis have nukes, I don't even think the US would be interested in a peaceful nuclear program for the Saudis, despite the talks. The Saudis have this part now (and probably even more) covered through their deal with Pakistan.
https://www.sciencedirect.com/science/article/pii/S2211467X2500094X
I think so too and obviously the Saudis think so too
Completely agree!