Assembling the fighting force to prevent a disaster would require a massive build-up in the region, something that the U.S. cannot do without tripping the caution light to the Iranians.
Put simply, a narrow attack on Iranian installations could result in a catastrophe without enough contengencies in place. Such contengencies would be obvious to the media hounds, thus tipping off the Iranians. Bottom line, we haven't seen such a build-up yet. Thus I don't see it happening.