“The involvement of the Iranian regime in supplying its Houthi militias with missiles is
considered a direct military aggression by the Iranian regime and may be considered an act of war against the Kingdom,” the crown prince was quoted as saying during a telephone conversation with British Foreign Secretary Boris Johnson.
http://www.arabnews.com/node/1189641/saudi-arabia--
In the case of a Saudi-Iranian war, it would essentially boil down to a draw due to many factors, UK and US would, of course, support SA. Oil prices would balloon, a good deal of Saudis and Iranians would die, shipping would be diverted if not stopped altogether in the Gulf, bad stuff. For military analysis:
https://www.youtube.com/watch?v=7a4sUtze3jwEdit:
To add to that, this article sees a war as beneficial to Russia, US fracking, and Saudi prices. This is a sad but realistic view of an almost guaranteed outcome and why MBS may not mind risking it. If he wins the war, higher oil prices, higher IPO, solidification of his image as a glorified war victor, etc.
This would be the greatest fantasy of many oil state Republicans.
https://www.forbes.com/sites/panosmourdoukoutas/2017/06/25/the-coming-war-between-saudi-arabia-and-iran-will-make-american-frackers-very-rich/#7024d6da78da