Comment by drnick1

> The best-case outcome is that this is a successful regime change operation which nets the US a resource-rich trading partner, undermines Russia, and scares Iran.

There is no need to scare Iran. The mullahs are already scared shitless and were utterly humiliated this summer. They could have easily been removed, but it was decided that it was not worth it, as the next regime could be even worse. A weak, scared Iran is the best outcome.