I felt giving a primary reason would add clarity, which is why I asked. So is “prevent another nuclear breakout from happening” the primary reason?

I do note that a similar reason was given for North Korea which did end up rather peacefully acquiring nuclear weapons.

Edit: so to confirm that is your stated primary reason? Any other reasons you can think of?

Primary reason is because Israel and American zionists (mostly evangelical christians) lobby for it. The KSA and friends also lobbying for it is just icing on the cake for American politicians.