Given the US didn’t jump into the MidEast as a kneejerk reaction, immediately, I’d say we aren’t going in at all.
The reason is really simple, because now DC has had time to think for a minute with a clear collective head.
You do not go to war to protect your trading competitors. Not ever. It would be stupid as hell to do that.
When the fracking industry in the USA started exporting oil products, the days of the US protecting the Saudi’s were over. It was just going to take a while to unwind. And it has been unwinding, while the House of Saud pretended it wasn’t.
And this is a twofer, not only are we seeing damage on the competitors in the oil business, we are seeing both damage to Europe’s trading posture in the world (because Saudi is their backup energy supply) and we’re going to be selling them more fuel (which is a bad thing, because it’ll be LNG, anyone who wants that discussion, just ask) and exporting more product, because Europe’s (and Britain’s) products will cost more to produce.
What’s not to love? We’re going to spoil that by jumping into a war that has never been ours? To save a BUSINESS RIVAL?
That would be like the US jumping into WWII to protect Japan (our business rival at the time) against China (a customer).
You DON’T do that.