If the zionist entity collapsed first it would take the US down with it and the US knows it and would use nukes to prevent whatever party is trying to take down the zionist entity from succeeding. For one the zionists might nuke or dirty bomb the US in revenge either directly or via selling such weapons to a pawn like ISIS that they turn on the US. For second even if they don’t their intelligence officials have infiltrated every level of tech at all major companies and information security in the west and implanted backdoors which they will use to bring down all water, power, information systems and destroy the economy of the west in retribution via their tech Samson option and the west knows this but cannot do a thing about it.

Saudi Arabia is also not full of bloodthirsty white supremacist fascists like the zionist entity. It’s a bad replacement because it’s population doesn’t see itself as white, isn’t democratically represented by the princes (democratically the Jewish population of the zionist entity fully supports the genocide, apartheid, and colonial expansion against Arabs by contrast). And Saudi Arabia doesn’t guilt Europe into supporting it on the basis of some past atrocity or history of racism.