Saudi Arabia under Crown Prince Mohammed bin Salman has been cozying up to the Russians. Recall that Saudi officials wouldn't take Biden's phone call a couple of months ago when Biden was pleading for countries to pump more oil, the U.A.E. also snubbed him. That's a very significant slap in the face to ignore the U.S. president, a really bad sign for U.S./Saudi relations.
The Iranians are already in bed with the Russians. If Saudi joins them then U.S. influence in the Middle East is greatly reduced. Russia, Iran, Saudi Arabia, and the UAE control a LOT of oil. That alliance will almost lock the U.S. out of the Middle East and like it or not, it's a very significant area to our national security.
This could be really bad.
It’s probably not so great for the Russians either.
If Saudi Arabia and Iran can solve their differences, it opens the door for cooperation between Saudi Arabia, Tukey, Iran and Pakistan.
This would be a 420 million population, nuclear-armed Muslim alliance with strong ties to Central Asia and the rest of the Middle East. If you include Syria, Iraq, and Egypt, that’s another 160 million