I'm most interested in the how rather than the questions of why Israel may decide to attack, what can be achieved, and what happens after.
This is their map of the Iranian target set:
I've read that an Israeli strike would require 100 planes to launch a basic strike. You can believe it wouldn't be enough or wouldn't last long enough. But let me start with 100 figher planes in a bombing role as the basic force Israel has to work with.
We have to start with the range issue (from the CRS report above):
Israel has five KC-130s and four 707-based tankers similar to American KC-135s. A 2009 study estimated a need for 12 tanker equivalents per mission simply to attack Iranian nuclear facilities at Esfahan, Natanz, and Arak (the Fordow facility had not yet been revealed). Without additional tankers, the fighters would have to refuel twice over the duration of the mission. This need may be somewhat reduced by the fact that Israel is also believed to have “mastered the operation of ‘buddy refueling,’” using the F-15s’ drop tanks to refuel the shorter-range F-16s en route. Additionally, one Israeli report states, “For the last few years, Israeli representatives have been snapping up every old Boeing 707 airliner in good condition … and converting them into airborne tankers. According to various sources, the IAF has by now eight or nine such tankers.”
Apparently (from Wikipedia), Israel used a single tanker to refuel 8 planes for the 1985 strike on the PLO headquarters in Tunisia, once on the way in and once on the way home.
Starting with the basic 9 tankers, that would give Israel the ability to send 72 planes out (and then refuel them on the way back in case they burn a lot of fuel over the targets) that could hit buried targets with penetrating smart bombs. The CRS report says Israel may have 4 or 5 more 707-based tankers but I'll ignore those for now. Using fighter planes with buddy systems on 28 planes could refuel 28 of the strike planes on the way in and out, so Israel can get 100 planes over the target.
To me, the biggest problem isn't getting 100 planes over their targets but getting 100 planes over their targets without the Iranians finding out. Launching 100 strike planes, 9 tankers, 28 buddy-refueling fighters, and whatever other supporting planes for the strike is going to be noticed. It will take time to organize those planes and by the time they can get to Iran, Iran will be alerted.
So Israel needs ways to reduce the strike force package to well under 100 to speed up the formation of the strike packages and get over Iran before Iran can be warned and alert their air defenses and scatter their movable assets.
Unlike past assumptions of mine, I'll rule out using Israel's ballistic missiles. Even if equipped with GPS warheads, the risk of having those missiles fail would undermine Israel's nuclear deterrent.
What if Israel has snapped up those 707s for use not as refueling aircraft as advertised but as bomb trucks. If Israel has 8 707s set up as bomb trucks with hard points under the wings, let me assume that each 707 can replace 5 strike fighters. That reduces the Israeli mission package to 60 planes. The 707s, with their hard points perhaps rigged to be jettisoned, could land nearby--say in Azerbaijan--without ruffling feathers as anything other than civilian craft looking for a safe place to land in a crisis.
What if the Israelis can ship off a sub within range of Iranian targets to use cruise missiles for targets that don't need penetrating munitions. Surely, not all targets are buried. Let's just assume a round 10 planes can be substituted this way. Heck, it doesn't even have to be a sub. If those are watched too closely, maybe the Israelis rig up a container ship with cruise missiles or even ballistic missiles in shipping container launching boxes. Maybe the Israelis even put such a ship (or ships) in the Caspian Sea to come from a completely unexpected direction? Russia sells those, after all. Anyway, now we are down to 50 strike planes.
Could commandos, agents, or Iranians working against the mullahs substitute for planes? Probably not many. Let's say 5. Now we are down to 45 strike aircraft.
What if Israel has arranged for some small number of planes to be based nearer to Iran in order to load them up with more weapons? Could Israel manage to slip even 10 fighter planes closer to Iran in some improvised road-based air strips in northern Saudi Arabia, eastern Jordan, Azerbaijan, or even western Iraq--with or without the cooperation of any of them (that seems unlikely, but who knows?)? Load them up with double the weapons an Israel-based fighter could carry so Israel reduces the number of strike planes taking off from Israel to 25--perhaps all F-15s. The planes based closer to Iran could then use Israel's refueling planes to reach home while the ground crews in the hasty bases bug out except for small numbers to destroy damaged aircraft that need a place to land and to get the pilot out.
If we are down to 25 fighter planes taking off from Israel because Israel has 75-Israel-based-fighter equivalents from other sources, Israel could contemplate getting that number off with their supporting aircraft without automatically triggering an alert in Tehran. And if the Israelis time their strike with a particularly bad Hamas or Hezbollah outrage that requires a big Israeli air response, the Iran strike could be lost in the local crisis as Israeli aircraft scramble to pound terrorist targets nearer to home.
I'm just trying to think outside of the box of US technology- and asset-based calculations, and my subtractions are all just WAGs, of course. But I think that reasoning like that could get the Israelis to a place where they can think they can strike without telegraphing their mission. Remember it does no good to simply say Israel can't do the job. If they think they must do the job to preserve their country, they'll find a way to make the math work out.
They could be wrong about their math, of course. But if they think they did it right, they'll strike.
