"In return, the US will provide protection to Saudi oilfields"
Interesting wording.
The Saudi oilfields are nowhere near the actual seats of power within Saudi Arabia. They are not near Riyadh. They are not near Jeddah. They are not near Mecca.
The oilfields are on the far eastern region of the country, along the Persian Gulf.
Why did the agreement specifically state we would protect the oilfields a d not the country (or royal family) as a whole?