Short answer: they know that if we really go down, so do they. For starters, about a third of their populations start starving to death, which means revolution. However, they were used to competent opposition, so they played hard to maintain a strategic edge. They are now realizing that obastard is both incompetent and a Muslim Brotherhood symp, and they’re getting desperate to stave off what they have wrought.
If the Saudis really care about saving their Wahabi butts, they will change the hate curriculum in their Islamic funded schools in the US, and the Madrassas throughout the world. Hotbeds of a kind of fundamentalism that will destroy them from within.