Israel will be fine on its own. It is armed to the teeth with US-made technology and upgraded by their own systems. As long as wealthy Sunni Arab countries stay out of the fray, Iran can do little but threaten shipping in-and-out of the gulf. The only real threat is that someone will conduct a terrorist action against us with Iranian backing, at which point here we go again. There is nothing that would please China more than the US navy occupied in the protection of worthless sand.
Regardless, Americans will pay. If not for weapons, then for oil and the commerce that depends on it. Say "Hello" to higher prices.