A pair of postgraduate students at MIT have produced a detailed assessment of the Israeli Air Force's ability to destroy Iran's potential nuclear weapon manufacturing plants.
Whitney Raas and Austin Long, PhD candidates in Nuclear Engineering and Political Science respectively, published (pdf) Osirak Redux? Assessing Israeli Capabilities to Destroy Iranian Nuclear Facilities last month. The title alludes to the famous Israeli air raid on Saddam Hussein's Osirak reactor in 1981, which destroyed the facility and denied Iraq any chance to build nuclear weapons in the 1980s.
Raas and Long suggest that a "strike package" of 50 US-made F-15 and F-16 jets - a considerable proportion of the IAF's current strength - could potentially wreck Iran's ability to build nukes, using conventional weapons already in the Israeli inventory.
The two eggheads believe that this could be done by destroying the uranium conversion facility at Esfahan, the heavy-water plants at Arak, and of course the biggy - the underground, heavily protected uranium-enrichment centrifuge bunkers at Natanz. Other targets in Iran, such as the Bushehr reactor, are assessed as being genuinely civilian in character and of no relevance to nuclear weaponry.
Esfahan and Arak could be dealt with comparatively easily, requiring no more than a dozen weapons each to wreck, according to Raas and Long. But the large, hardened subterranean centrifuge arrays of Natanz would be more difficult altogether. To have a serious chance of drilling down through layers of earth and concrete protection, the report suggests that Israeli jets would need to drop 12 5,000 pound BLU-113 penetrator bombs, and then another 12 exactly into the craters made by the first lot. This sort of accuracy could be achieved only by the use of laser guidance: GPS-steered weapons would not suffice.
Raas and Long note that this technique has been considered in the past by the US Air Force, and mentioned publicly by IAF general Eitan Ben-Elyahu, who participated in the original Osirak raid. Even so, the Israelis probably wish they had a mega-penatrator option like the 30,000 pound whopper the Americans are currently working on.
The two authors also admit that under some of the more likely planning options, Israeli F-15I "Ra'am" jets could each carry only a single BLU-113 to Natanz; and that the IAF possesses only 25 of these aircraft. Only a little would need to go wrong for the Israelis here - a jet or two going titsup, getting shot down, or being compelled to dump weapons - and the Natanz hit might not be fully effective. If just 1,000 centrifuges of a possible 50,000 remained serviceable, Iran could still enrich weapons-grade uranium, albeit much more slowly.
Raas and Long skate over the massive diplomatic problems that would accompany an Israeli strike. The planes would have to fly over Turkey, Syria, Jordan, or Saudi Arabia: and/or American-occupied Iraq. Turkey and Jordan would be extremely angry, but conceivably might not shoot at the Israelis. Syria surely would. America probably wouldn't, and arguably would have to be consulted in advance anyway, but all in all the Israeli airmen might have to fight before they even reached Iraq, and perhaps again before they got home. The two authors are surely correct to assume that Israel could never get away with more than a single lightning raid; international outrage would surely prohibit any sustained campaign.
Some analysts have taken this report to indicate that Israel could destroy the Iranian nuclear capability almost any time it feels like it (or any time it thinks the Yanks won't get too upset). The authors themselves conclude that "Israeli leaders have access to the technical capability to carry out the attack".
Alternatively, one might say that from the Israeli viewpoint the strike would need the entire fleet of F-15I Ra'ams to be serviceable; it would need neutral or hostile governments to be complicit or at least inactive; it would require a larger air-refuelling fleet than the IAF has - or alternatively very little fighter cover; the Natanz bombers in particular would need to arrive almost uninterfered with; and in the aftermath there would surely be a massive political price to pay.
That's a big accumulator bet to make, especially when one considers that even if Iran were nuclear armed and able to attack Israel, the Israelis could still rely on their own nuclear weapons for deterrent effect.
On the other hand, Raas and Long have seemingly ignored other options available to Tel Aviv. Israel is nowadays believed to possess submarine-launched cruise missiles, which could easily be launched from the Arabian Sea or the Gulf to hit Iranian targets.
The problem with that, of course, is that subsonic low-flying weapons like the Israeli "Popeye Turbo" couldn't crack the Natanz bunkers using conventional warheads - at least not in the current state of the technology. The submarine option would require the use of nuclear weapons, which probably doesn't seem like a brilliant idea even to the Israelis - let alone the rest of the world.
Which is probably why the MIT guys didn't choose to open that particular can of worms.
One thing's for sure: student life seems to have changed a lot since our day. Maybe Raas and Long need to get down to the pub a bit more. Or just join the damn Air Force, already. ®