Playing the role of the "adults" in this story are his Secretary of State, Rex Tillerson, and his Secretary of Defense, (General) Jim Mattis.
Past Presidents, both Republican and Democratic, have tried to stay relatively neutral on this situation. There are lots of reasons, but we can start with the fact in Syria we are fighting ISIS (a Sunni organization) and are de facto allies with Iran.
Another great reason is that Saudi Arabia is the chief exporter of Wahhabi-ism, the most virulent anti-Western form of Islam.
But if Obama liked anything, Trump must hate it. So he did a little impotent sword dance* and gave his blessings to the King.
Saudi Arabia then turned immediately and has threatened Qatar. The President, with his great depth of Middle East knowledge applauded that action and took credit for enabling it.
Problems?
Well, Qatar (1) hosts our Naval Port in the Persian Gulf, (2) hosts our Air Force Base for supporting our troops in Syria and Iraq - and the origin for our bombing ISIL. It has the only (3) free press in the Middle East (outside of Israel). It (4) is useful whenever the US wants an off-the record discussion with a nation or group we can't talk to like (used to date for discussions with) (5) Iran and (6) the Taliban. It also (7) hosts our NATO ally, Turkey's, military base in the region.
Our Secretary of State and Secretary of Defense both are trying to discuss this situation and fix it. The President has, repeatedly, trashed Qatar and taken credit for isolating it. It isn't that Trump is stupid, it is that he is actively ignorant of the facts on the grounds and refuses to learn them or ever admit to an error.
Fun.
*Sword dance in need of a case of viagra...
