[ArkyBeagle]

This is also true as a practical matter - there's no real mechanism for forcing officials of another country to provide information. Congress cannot change this.

People in Saudi who are dissidents end up jailed. This is particularly acute about the Shia/Sunni axis.

The Saudis may well have a legitimate complaint here - the result would possibly be a historical fiction made up for political gain.

Interestingly, I would think that Congress commissioning a rigorous investigative nonfiction film - of the sort Errol Morris does - would be a better solution. "Frontline" already has a start on the subject. The hard part would be defending the design of that from accusations of it being propaganda.