It's not a pretty picture under any circumstances, John. I don'y know how accurate our intelligence is from that area at this point. In general, I'm not happy with it. I believe we don't have much penetration of Israeli intelligence, and I don't have any idea how factionalized they are or the Israeli government is. This is, as you suggest, a major element in determining the outcome.
While were are supposed to have an alliance with the Saudis, I am not clear about the nature of that. How good a grip the House of Saud has on the government is unclear, and the extent of their bargains with the Wahabist folks means that whatever they say to us will still need to get the okay on some level with the Religious Islamic Right over there. The House of Saud will feel a need to say Yes out front to as many people as possible, because No is politically dangerous in that culture (and perhaps in politics in general, if you think about it). The actual Nos will come in the form of delays and unforeseen circumstances and accidents and apologies and unexplained cancellations. We like to think we're much more straightforward in the U.S., but I tend to think that Politics is Politics the world around. The arabs are simply a bit more flowery about it.
If all the hoopla we were hearing 15 years back about loose nukes in the break-up areas of the old USSR was true, it seems there may well be a nuke in some sort of condition floating around the area anyway, and probably under Iranian control. Perhaps I'm simply being a wild man in thinking this, but the quarrel we're having right now is about the Iranians developing their own capability to build their own nukes, not about whether there's one sitting around someplace that could be used if somebody wanted to use it. We don't want Iran to have their own dependable nuclear capability, with more than one or two dependable bombs and the means of delivering them in such as way that they would be hard to stop as a weapon of war. If they were used as a terrorist weapon, I think it would change the nature of how the world would look on terrorism. Now it's a real annoyance, but it's found a niche where the response is just short of a serious major war for those who even look they sponsor a successful midrange terrorist attack.
Detonation of a nuclear weapon would, I think change the correlation of forces, and would provoke a seriously savage counterattack with 1)either a significant amount of world support; or 2) a seriously polarized world response which might break down into a nuclear version of the events that lead up to World War I as alliances dragged unwilling participants into an ever-growing nuclear exchange.
Hopefully, most folks are too fond of their hindquarters to risk such an exchange for the possibility of limited gain. Our job as a super-power, I would imagine, is twofold as well. Make sure that people realize the level of consequence remains high. Make sure that the level of reward for not pursuing such a course remains diplomatically and economically high as well. Everybody needs to feel they're getting something of a share of the wealth and that a rising tide is, in fact, floating all boats.
That seems to be a response that might be useful.
The problem is that everything is so vague, it's hard to break down such a general outline of possible future events into potential future plans, or even find some sort of markers to look for to see what sort of clues we should look for that might lead us to which sort of outcomes. I think I'm simply going to have to start warming up the old Tarot Deck, and start working the Yarrow Sticks to see what The Superior Man should do. Confucius, here I come!