Saudi Arabia has been a false friend over the years and recently determined to be behind the 9/11 terrorist attacks on the U.S. It was determined that Saudi Arabia provided the financial backing to fund the 9/11 plot. The U.S. should sanction Saudi Arabia and be cautious of any relationship with that country.
The United States has benefited from close ties to Saudi Arabia since the 1930s, and there is little reason to relinquish that trust now. In regards to claims on their involvement in 9/11, the United States already gave victims a channel to sue the Saudi government, an action that is usually avoided in all foreign policy. Furthermore, the trade item that is the most contentious is indisputably the weaponry the United States sells to the Saudi government. Although it is being used to fight the Yemeni war, which has created many human rights violations, they are also used to combat terrorism, like Al Queda, which again comes back to the 9/11 point. In the end, one thing is clear: allies are allies, and there is no reason to mess with that. Saudi Arabia has been a friend for years, and the United States relies on them for trade, oil, and counter-terrorism. Giving that up would be the death of the country.
The United States depends so much on Saudi Arabian oil though the conflicted country could very well be supporting and funding terrorism, but Saudi Arabia should not be sanctioned. Studies show that money is difficult to track in Saudi Arabia, and proving national or public contributions to terrorism is nearly impossible. No judicial entity can ethically hold an entire country accountable for the actions of a few.
Saudi Arabia represents an important economic ally of Western states, and one of the few prosperous Middle Eastern countries that is not facing widespread political instability and poverty. Although factions within Saudi Arabia have been suspected of supporting known terrorist organizations, there is little evidence that the ruling government has been involved. Sanctions would send the wrong message at a time when the Iran nuclear agreement has already caused strained relations between the United States and Saudi Arabia.
The best way to sanction Saudi Arabia is to stop having so much dependence on their foreign oil. We need to create solar powered vehicles and rely on our own oil. This will help to bankrupt them. They have made their wealth off the backs of Americans and had a lot to do with 09/11 but there is nothing we can do about that now without catastrophic events. The irony of life is everything comes around full circle. There are now terrorist on their backdoors for them to deal with. They thought it was a West problem but not so fast...look who's knocking on their door, their own creation.