Iran's nuclear targets are spread throughout Iran, but luckily for Israel the more immediate targets (that we know about) are located in the western half of Iran. See this map. I'd guess that the map shows eleven must-hit targets that represent the facilities that can be used to create and process nuclear materials directly useful for nuclear warheads. Mines and research facilities would not be hit from the air since these represent long-range threats and Israel doesn't have the assets to expand the target list from the must-kill targets to affect the near-term situation.
I assume no nukes will be used to disarm Iran. If Iran openly possessed nukes, I wouldn't say that Israel would rule out nukes to try and destroy Iran's nuclear arsenal. But in a preemptive attack, I think Israel stays conventional.
Aircraft will fly through Turkey and Saudi Arabia to reach Iran. But not too many aircraft to avoid telegraphing the punch. Israel can't hide the launch of a really large strike. The Israelis have practiced at the range they'd need to fly. And precision weapons means that single aircraft can hit multiple targets, reducing the need for numbers that would have been required even twenty years ago. I'm assuming that Israel could send in a force big enough to do some damage yet small enough to avoid easy detection.
Israeli aircraft might take off on the pretext of striking Hamas or Hezbollah. Some would attack those targets but the remainder would form up and head for Iran. It is always easier to disguise military activity than to hide it.
The Saudis are very worried about Iran, so I think the Saudis would look the other way while Israeli planes go through northern Saudi Arabia. The air attack on the Iranian rocket convoy through Sudan shows that the southern route is open through the Red Sea. There are four targets that could be hit from the southern route: the Fasa Uranium conversion site, the Bushehr light water reactor, the Ardakan Uranium purification site, and the Darkhouin Uranium enrichment site.
Could an Israeli AWACs-type plane reach the northern Persian Gulf before the southern strike aircraft arrive? Could it fly from India, perhaps?
Rescuing downed pilots in the south would be tricky without US cooperation to use Iraqi air space. Perhaps agents on the ground would have to help. Perhaps pilots would be told to fly to Iraq to land crippled planes or fly and ditch in the sea to hope for American help for rescue after the fact. Or maybe helicopters on make-shift merchant ship landing pads would be used to send in helicopters for rescues.
The strike on Syria's North Korean-built and Iranian-funded reactor shows that Israel could skirt the Syrian-Turkish border, perhaps mostly crossing Turkish air space while claiming their planes only went through Syrian air space and Kurdish air space in Iraq. Targets that could be hit from this direction include five locations: the Chalus weapons development facility, the Ramandeh Uranium enrichment facility, the Lashkar-Abad Uranium enrichment facility, the Khondab heavy water plant, and the Arak heavy water reactor.
Some aircraft might already be in Turkey for "exercises," reducing the refueling burden for planes flying from Israel while still allowing Turkey to deny that any aircraft took off from Turkey for the attack. Perhaps an Israeli AWACS aircraft flying over eastern Turkey would help control the strike package from this direction.
Helicopters to rescue any downed pilots would have to stage into eastern Turkey.
The strike would not go through Iraq to avoid needing to get our permission and cooperation. I don't understand why people keep insisting that Israel must go through Jordan and Iraq. The Israelis simply don't have to. And their Sudan and Syrian missions demonstrate partial routes around Jordan and Iraq.
I don't know nearly enough to say how many aircraft would be needed for each target. Some might be point targets and some might be complexes. Some might have buried facilities. But each aircraft would carry multiple precision weapons so I'd think that Israel could do sufficient damage. Even the small number of aircraft that would escort the strike packages could carry a smart bomb or two to launch from high altitude at the opening of the strikes where they'd then fly cover. Depending on the timing of reaching the various targets from two different directions, I can't imagine the time over target for the aircraft would be more than 15 minutes (athough admittedly this is a WAG).
Fighter cover would have to stay longer if rescue helicopters were in the air over Iran. Or maybe Israeli pilots would be told rescue is too difficult to arrange. Nurse your bird to friendly territory or you're on your own.
Missiles based in Israel might be part of the strike. These might be used for the more dangerous inland targets like the Yazd milling plant and the Natanz enrichment facility. Missiles might also be used for follow-on strikes as the aircraft withdraw in order to hit any targets that appear to still be intact based on satellite and drone imagery. They'd have to fire after the air strikes start dropping bombs on target to avoid telegraphing the attacks.
Submarine-launched cruise missiles from Mediterranean might also be used for such follow-on strikes. The range and flight time are too great for cruise missiles to be used in the initial strike. I doubt Israel could get a sub into the Arabian Sea without it being noticed during transit.
I suppose it is always possible that Israel could outfit a merchant ship with cruise missiles and send that into the Arabian Sea to open up the southern arc to cruise missile strikes in the first wave.
The follow-on cruise missile and ballistic missile strikes might be used to hit Iranian long-range ballistic missile sites as a secondary mission if the initial air strikes appear to have done enough damage to the priority nuclear targets.
The follow-on missile strikes could also be used to cover the withdrawal of the aircraft, rescue helicopters, and any ground elements, by making it seem as if the attacks continued, delaying Iranian reaction.
Special forces and intelligence operators could also be part of the strike package. The Bushsher reactor might be hit with commandos from the sea who either try to penetrate the reactor to disable it if there is worry about radiation release from air attacks, or guide in the air strikes if that isn't a concern. Ground teams might set off explosions in other potential nuclear targets or near Iranian political targets even in Tehran to sow confusion about the scale of the attack, which might delay effective reaction to the main efforts.
If Iran strikes Israel or even America in retaliation (NOTE: I mean American targets close to Iran, obviously, and not America itself.), will we be able to blunt the counter-strike (possibly using chemical weapons) with our combined anti-missile systems?
Of course, that would be an Iranian provocation that would allow us to finish the job with an aerial campaign lasting weeks. But that assumes President Obama is willing to wage such a war. As I've said, he'd get the Nobel Peace Prize if he did destroy Iran's nuclear program.
I'm no expert in air attacks or Iran's nuclear infrastructure. This is just a shallow, framework of a guess based on what I'm guessing is possible if Israel decides to strike and if Israel pulls together the assets. Israel seems to either have the pieces to execute this type of attack or could get the pieces.
Still, Israel has already had years to work this problem. And they may have more time to plan to get the most of their assets and to fill in gaps in their capabilities. And gain the quiet cooperation of states like Turkey, India, Saudi Arabia, and Jordan, as long as Israel agrees to publicly take all the blame and deny they got any help. Arab states seem to understand that even slowing down Iran's nuclear drive is necessary. Although slowing down Iran from their point of view might just be with an eye to gaining the time to build their own nuclear arsenals. (More reason we should do the job.)
Secretary Gates says Israel is unlikely to strike this year. So Israel still has time to put the pieces together. This wouldn't be Israel's Plan A. It might only buy time. And it might even fail. But when the alternative is Iran under the mullahs with nukes, I think they'll try--regardless of what the actual strike would look like. And regardless of the longer-term problems that might develop.
My hopes that we'll engineer a revolution in Iran to eliminate the need for anybody to contemplate a military strike have faded to virtually nothing in the last several years. My hopes haven't risen in the last several months.
QUICK UPDATE: I just saw this article that says Israel is ready to attack if given the order. I guess they have the pieces. I still don't understand why this statement by an Israeli intelligence official is taken at face value:
He added that it was unlikely that Israel would carry out the attack without receiving at least tacit approval from America, which has struck a more reconciliatory tone in dealing with Iran under its new administration.
An Israeli attack on Iran would entail flying over Jordanian and Iraqi airspace, where US forces have a strong presence.
No, Israel does not need to attack through Jordanian and Iraqi airspace. Look at a map. It would be nice if crippled aircraft or rescue helicopters could enter Iraq to land in an emergency, but for the attack itself, that is simply not necessary.