"Loyalty only matters when there's a hundred reasons not to be-" Gen. Mattis
You can never have a truly trustworthy relationship with devout Muslims. They always carry those sharp knives - they claim it's a religious thing.
"The king combines legislative, executive, and judicial functions and royal decrees to form the basis of the country's legislation. The king is also the prime minister, and presides over the Council of Ministers (Majlis al-Wuzarāʾ), which comprises the first and second deputy prime.
The royal family dominates the political system. The family’s vast numbers allow it to control most of the kingdom’s important posts and to have an involvement and presence at all levels of government."
There is no reason to think that the Saudi government reflects the will of the people. If Obama let Saudis build a military base in the USA you can bet conservatives would have a fit and be angry and offended for religious and other reasons.