Ideally, no one should have nuclear weapons but they exist so we're left with asking how to deal with proliferation.

In my opinion, a state run by a Wahhabi theocracy should prevented from getting its hands on nuclear technology. They are an ally only in the sense that they have the deepest oil reserves and use their economic clout to get their way. They are also an ally to the US because they bring some semblance of stability to the ME region.

But KSA funds insurgents intent on destabilising Europe and it's not behaviour of an ally imo.