As tensions continue to rise in the Middle East, many news organizations have frequently discussed the possibility of an Israeli strike on Iranian nuclear facilities. The purpose of this article is to determine how, if possible, could Israel attack Iranian nuclear facilities? First and foremost, the number of variables that would be involved in such an operation is staggering. As a matter of practicality, some details must be overlooked for the sake of brevity. The following should be considered
- Circumstances leading up to hostilities
- What is the objective? Bombing Iranian nuclear facilities will likely set back Iranian nuclear efforts but risk of not completely eliminate the threat.
- In relation to objective, time frame of operation? How to end conflict and what will be the determining criteria for deescalating conflict?
- Extend of U.S involvement if any: none or logistical to deploying combat assets
- Route in which Israeli aircraft fly into Iran
- How will Israeli overcome the Iranian IADS and to a lesser extent, the Iranian Air Force
- How many targets and which ones does Israel target? Israel has a limited supply of bunker busting munitions and extent of hardening Iranian facilities archive. U.S involvement critical to this variable.
- Iranian counter attack on Israel with missiles: possibility for missile attack on U.S bases in region, possible launches on Saudi Arabia if country is complicit with Israel. Response to Iranian missile threat and possibility of extended conflict needed by allied forces. Iran knows Israel maintains a nuclear deterrent, this may effect Iran's decision to use its chemical weapon arsenals.
Note: This analysis will examine a scenario in which Israel launches a surprise aerial attack into Iran to hit critical nuclear facilities. This analysis will be conducted with current equipment e.g. Israel will not have access to stealth aircraft. Attacking Iran's nuclear facilities would be a measure of last resort and not be undertaken lightly e.g. Iran is weeks away from developing nuclear weapon grade uranium. Initially, the analysis will assume that the United States is not involved for Part I.
Any Israeli operation within Iran must be centered around a clear measurable objective with an abundantly clear exit strategy. For example, the most probable objective would be destroy nuclear facilities and eliminate only critical Iranian assets that would impede such an operation and exit Iran as quickly as possible. Israel would only want to disable the nuclear facilities as to avoid the risk of a protracted war with Iran. A quick efficient method of determining the success of the airstrikes is needed. It is probable that Israeli satellites and UAV's will be used to determine the level of effectiveness of any bombing attempts. Even if the United States was not militarily involved, it is likely that the United States would share intelligence gathered from its surveillance platforms with Israel. If the nuclear sites are deemed destroyed or put out of service then it is unlikely that Israel would not seek further conflict with Iran and withdraw. Iran knows Israel maintains a nuclear deterrent, and may or may not risk further hostilities. This will be discussed in Part II.
List of Targets
Before any strike is carried out, a list of targets must be compiled. Iran currently maintains several nuclear program related facilities. Determining which facilities are most vital to the Iranian nuclear programs and destroying those facilities is key if the objective is prevent Iran from obtaining a nuclear weapon. Ideally, several individuals with extensive expertise in creating and maintaining nuclear reactors and nuclear weapons would be consulted to determine which facilities are most vital. Because I do not have access to such expertise, the following are priority targets are listed by several respectable sources.
Natanz
Fordow (Qom)
Parchin
Esfahan
Arak
Route to Iran
List of Targets
Before any strike is carried out, a list of targets must be compiled. Iran currently maintains several nuclear program related facilities. Determining which facilities are most vital to the Iranian nuclear programs and destroying those facilities is key if the objective is prevent Iran from obtaining a nuclear weapon. Ideally, several individuals with extensive expertise in creating and maintaining nuclear reactors and nuclear weapons would be consulted to determine which facilities are most vital. Because I do not have access to such expertise, the following are priority targets are listed by several respectable sources.
Natanz
Fordow (Qom)
Parchin
Esfahan
Arak
Route to Iran
In order to strike targets within Iran, the Israeli Air Force (IAF) must traverse at least one other country to reach their targets. The image below shows possible air routes into Iran. Any attempt to fly over Syria seems highly unlikely. Not only is Syria a staunch ally of Iran, but also Syria has a formidable integrated air defense system (IADS) of its own. Even disabling portions of Syria's IADS would be needlessly complicated if other routes are available. Unfortunately, political relations play a role into which routes are open to Israel. I am not a political or diplomatic expert. From the limited knowledge I do know on the subject, routes through Jordan and eventually Saudi Arabia seem to be the most likely followed by the possibility of traveling through Turkey. Saudi Arabia has no desire for Iran to acquire nuclear weapons and has been at odds with Iran for much of the past decade. In this event, Saudi Arabia would have to deactivate its IADS or have capable IFF (identification friend or foe) recognition systems in order to limit friendly fire. Assuming this is a surprise attack, only the most crucial individuals would have knowledge of the operation prior to its initiation. At some point Saudi forces must be alerted of the incoming Israeli aircraft even if it increases the risk of alerting Iran.
For example, on New Year's Day of 1945, the Luftwaffe launched a surprise all out air campaign against Western Allied forces in conjunction with the Battle of the Bulge. The air campaign was called Operation Bodenplatte and was kept in total secrecy by the German leadership. The German Flak Anti-Aircraft-Artillery forces had not been informed of the upcoming operation and thus fired on their own aircraft. This resulted in the loss of around 200 German aircraft out of the original force of 800 aircraft solely from friendly fire. Operation Bodenplatte broke the back of the Luftwaffe and Nazi Germany was never able to claim air superiority for the rest of the war. In summary, coordination between the Saudi's or Turkish military and the IAF will be paramount. The IAF cannot afford to sustain needless fire casualties in route to Iran.
Another key factor is range. Due to the extensive distance of Iranian targets from Israel, all seven of Israel's tanker aircraft will likely have to be used in this operation (KC-707). The limited number of tankers in the IAF inventory will severely limit the scale of the strike force to a couple dozen Israeli aircraft. This will have a profound impact on the scope and limits of the operation as discussed throughout this article. A journal article published by Middle East Quarterly indicated that two to three full squadrons (48-72 aircraft)
“The Israeli Air Force is capable of striking the necessary targets with two to three full squadrons of fighter-bombers with escorts to shoot down enemy aircraft." - Iran's Nukes and Israel's Dilemma, 2012
(Image 2: Potential air routes into Iran)
The Iranian Defense
Before we discuss the methods Israel would likely use to defeat the Iranian IADS, a quick look at Iranian Surface to Air Missiles (SAM) and select aircraft will be given.
The Iranian IADS is largely composed of Cold War relics originally designed and built between the 1950s and late 1960s. Arguably the most formidable of Iran's SAM systems is the Soviet built SA-5 Gammon (NATO designation: S-200) it received shortly before the collapse of the USSR. (Global Security, 2012) The Gammon variant deployed by Iran, the SA-5B (S-200VE) has a range of 200 nautical miles. NATO forces encountered a number of SA-5 missile sites in Operation Odyssey Dawn within Libya and destroyed them with relative ease through the use of cruise missiles in conjunction with electronic warfare. Though the SA-5 was highly capable SAM relative to other SAMs upon its original deployment in the late 1960s, its is now highly vulnerable to modern jamming equipment. Iran heavily relies on the S-200 for its national SAM coverage. (Air Power Australia, 2010)
(Image 3: Iranian SA-5B with launcher, retrieved through Air Power Australia)
The second main SAM operated by Iran is the 30 nautical mile capable HQ-2, a Chinese made copy of the Soviet designed SA-2 SAM system. Iran also operates the U.S supplied Hawk system it received in 1972. The Hawk variant operated by Iran has a much shorter range than the SA-5. Subsequently the Hawk would be used to target aircraft in similar ranges as the HQ-2. Iran also domestically produces a reverse engineered copy of the Hawk known as the Mersad which features moderate improvements.
The Iranian Air Force is a shadow of its former self. Prior to the Iranian Revolution in 1979, Iran had one of the best equipped Air Forces in the region. (Global Security, 2012) Despite the current poor state of the Iranian Air Force, they still pose a credible threat to the IAF in this type of scenario. The extent of the threat posed by the Iranian Air Force will be determined by the number of aircraft they can mobilize in the wake of their disabled command and control abilities (due to cyber attacks). The most formidable fighters flown by the Iranian Air Force is the F-14 and Mig 29. Both of these aircraft are outmatched by the modernized upgraded variants of the F-16 and F-15 flown by the Israeli's. Furthermore, Israeli pilots are among the best (if not the best) in the world. However, the two to three squadron Israeli strike force will be very limited in the number of air to air munitions it can carry due to: the limited number of aircraft, the weight of the 5,000 lb GBU-28 bunker busters, external fuel tanks, targeting pods, electronic jammer pods, etc. (Some aircraft will likely provide dedicated escort others will be equipped with bunker busters)
Image 4: As to be expected, Iran's most vital nuclear sites are covered by multiple layers of SAM protection in addition to being in close proximity to Iranian Air Force bases. (Image Credit: CIA)
Defeating the Iranian IADS
The IAF does not currently possess stealth aircraft of any kind. Thus, Israel must rely on other proven technologies to defeat Iran's IADS. Contrary to popular belief, the use of stealth technology is not the only method in use to circumvent an opponent's IADS. Since the Vietnam War, electronic warfare equipment has been fitted to aircraft with the purpose of jamming enemy radar's and missile systems. Since that time, electronic warfare systems have grown in sophistication and effectiveness. During the Gulf War in 1991, the prolific use of radar jamming systems and other electronic warfare equipment aided Coalition forces in defeating the Iraqi IADS. Recent developments in electronic warfare include use of cyber attacks to cripple enemy command and control abilities in addition to feeding early warning radars and sensors false information.
Israel has already demonstrated its firm understanding of electronic warfare principles to bypass an enemy IADS. In 2007 Israel launched Operation Orchard within Syrian airspace. Intelligence sources had indicated Syria was developing a nuclear reactor with North Korean assistance. IAF F-15 Ra'am (modified F-15E) and F-16 Sufa (modified F-16D block 50/52+) penetrated Syrian airspace and conducted strikes against the suspected reactor site. No Israeli aircraft were lost in the operation.
Israel managed this feat through the use of electronic jamming and cyber intrusion attempts. It is likely that the Israeli Defense Forces have comparable software to the United States in this regard. BAE systems developed a system for the United States called Suter. The following is from Aviation Week regarding Suter:
"The technology allows users to invade communications networks, see what enemy sensors see, and even take over as systems administrator so sensors can be manipulated into positions so that approaching aircraft can't be seen...The process involves locating enemy emitters with great precision and then directing data streams into them that can include false targets and misleading message algorithms." - Aviation Week, 2007
A program like Suter would allow Israeli aircraft to fly into hostile airspace and avoid detection by enemy surface to air missile sites. By necessity, Israel has some of the most skilled cyber warriors on earth. The Israeli Unit 8200 is especially renown for its cyber warfare capabilities and jointly developed the Stuxnet computer virus along with the U.S National Security Agency. (New York Times, 2012) However, there are several problems that arise in comparing the success of the Suter like program in Operation Orchard to an airstrike within Iran.
One, it its unclear exactly how long Suter is able to disorient Iranian sensors and communications. Operation Orchard involved striking one target within Syrian airspace before quickly withdrawing back to Israel. Any raid into Iran with the goal of disabling its nuclear program, would have to target multiple hardened nuclear sites to be truly effective. Breaking through the hardened facilities with current Israeli bunker busters would take repeated bombing runs preformed with near flawless airmanship over the course of days. This method would take a great deal of time compared to the relatively unfortified Syrian reactor bombed in Operation Orchard.
Second, although Suter disables ground sensors and radars, it is unclear if it is able to interfere with the senors and avionics of aircraft e.g. Iranian Air Force. Because the IAF would have to cross at least one country (e.g. Saudi Arabia) before striking targets within Iran, the possibility exists that Iranian intelligence might be able to alert its Air Force to fly combat air patrols over its critical nuclear facilities. Even if Iranian ground based radar sites are unreliable, Iranian aircraft could still intercept incoming Israeli aircraft. It is clear that other electronic warfare systems would have to be used in conjunction with Suter to disable the Iranian Defense. Israeli cyber attacks would likely target Iranian communications to mitigate this risk. However, any open cyber attack could invoke alarm among the Iranian military and likely increase Iranian military readiness. Although a sophisticated cyber attack would greatly weaken Iranian command and control abilities, it is hard to eliminate every method of communication.
Although Israel has the electronic warfare equipment needed to mitigate the threat of the SA-5 missiles, the IAF cannot comfortably destroy the SA-5 missile sites from long stand off ranges. NATO forces in Operation Odyssey Dawn made extensive use of Tomahawk cruise missiles. Israel has no direct equivalent to the Tomahawk. (Possibly for limited use of Popeye turbo cruise missiles launched from Dolphin submarines; The Dolphin is not a dedicated cruise missile submarine, missile load very limited) The longest range air to surface missile available to the Israeli strike force would be the Delilah cruise missile with a range of around 300km (officially 250km but anonymous IDF sources reported to Jane's that the missile had a 300km plus range). Even with the more optimistic range estimates, the Delilah would have a range of around 162 nautical miles, vs the SA-5B's range of 200 nautical miles. Only a limited number of Deliah's and AGM-78 anti-radiation missiles could be carried thus only key SAM sites would likely be targeted.
In summary, the IAF could likely overcome key portions of the Iranian IADS for at least short periods of time with minimal to acceptable combat losses.
Delivering the Blow
(Image 5: Israeli F-15C's (Baz) would provide armed escort for the bunker buster laden F-15E's (Ra'am)
(Image 6 Credit: Washington Post, 2012)
Both Qom and Natanz utilize a form of ultra high performance concrete (UHPC). Iran
"Iran is an earthquake zone, so its engineers have developed some of the toughest building materials in the world. Such materials could also be used to protect hidden nuclear installations from the artificial equivalent of small earthquakes, namely bunker-busting bombs." - The Economist, 2012
Commercially available U.S UHPC have stress ratings in excess of 20,000 psi. (Ahlborn, 2012) Current GBU-28 in use by Israeli's can only penetrate 20 feet of 5,000 psi rated concrete. (Expect much less penetration around 2-3 feet with 20,000 psi rated concrete, explosion would slightly widen actual penetration) Thus, dozens of GBU-28 bombs would be required to completely destroy the facility at Natanz. The GBU-28 would make short work of the 72 foot dirt mound but would experience difficultly penetrating the remaining reinforced concrete slab (reinforced roof) and subsequent barrier (8 foot thick wall). Bombs would have to be dropped at the same point repeatedly to break through one area of the barrier.
(Image 7: Natanz facility. Image Credit: Institute for Science and International Security/GeoEye, retrieved through Wired)
Both underground cascade halls at Natanz would have to be targeted as shown in the image above. Because the halls are separated into into two different buildings, more bombs will be required to completely destroy the facility. It is possible that disabling Natanz alone would require half of the IAF's 100 GBU-28 stockpile.
The GBU-28 is a combat proven and effective bunker buster against less hardened 5,000 psi rated moderately deep bunkers. That said, Fordow (Qom) is nearly invulnerable to the GBU-28. The inner enrichment hall is buried by an estimated 80-120 meters (264-396 feet) of hard rock. The only chance Israeli pilots would have in destroying Qom is to target potential weak points such as tunnel entrances or ventilation shafts. Consistently hitting targets as small as a ventilation shaft, even with the tremendous skill of Israeli pilots coupled with the use precision guided munitions, is no easy or guaranteed task. Furthermore, there are a number of relatively low cost measures to mitigate the damage done by strikes to tunnel entrances or other weak points, e.g. burster slabs, that the Iranians can pursue. Although the Fordow facility contains less operational centrifuges than Natanz, it will be considerably tougher to destroy. Even if Israel was able to succeed in destroying the majority of centrifuges at Natanz, Iran would still have remnants of its nuclear program and by some criteria, the operation would subsequently be a failure.
Israeli forces would be also constrained by the time limit allotted for the operation. The longer the operation takes in duration, the more likely Iran will be able to mount a defense of its nuclear facilities. A former member of Prime Minister Netanyahu's staff, Natan Hendel, estimated it would take Israeli two days to disable Iran's nuclear infrastructure. I do not share Mr. Hendel's optimism.
Over the course of days with relentless around the clock air strikes, Israel could destroy unhardened Iranian nuclear facilities with relative ease. However, arguably the most important facilities, Fordow and Natanz, would be extremely difficult for the IAF to destroy. Of the two facilities, Natanz would likely be given priority as it is not as heavily hardened as Fordow (Qom) and represents a greater share of Iran's operational centrifuges (Natanz has 9,000 centrifuges and Qom operates 3,000 centrifuges). In summary, even if Israel suppresses or destroy's the Iranian IADS, Israel could not extensively disable or destroy, with credible certainty, all five of the facilities listed above in a short period of time. Iran would still retain a sizable remnant of its nuclear program (around 3,000 operational centrifuges) even after the hypothetical extensive bombing campaign. Once again, individuals with expertise in nuclear development programs would be required to fully assess the damage done to the Iranian nuclear program in the wake of these hypothetical results.
Part II will examine the possibility of U.S involvement and other factors e.g. Iranian missile counterattack not discussed in Part I.
Sources
Another key factor is range. Due to the extensive distance of Iranian targets from Israel, all seven of Israel's tanker aircraft will likely have to be used in this operation (KC-707). The limited number of tankers in the IAF inventory will severely limit the scale of the strike force to a couple dozen Israeli aircraft. This will have a profound impact on the scope and limits of the operation as discussed throughout this article. A journal article published by Middle East Quarterly indicated that two to three full squadrons (48-72 aircraft)
“The Israeli Air Force is capable of striking the necessary targets with two to three full squadrons of fighter-bombers with escorts to shoot down enemy aircraft." - Iran's Nukes and Israel's Dilemma, 2012
(Image 2: Potential air routes into Iran)
The Iranian Defense
Before we discuss the methods Israel would likely use to defeat the Iranian IADS, a quick look at Iranian Surface to Air Missiles (SAM) and select aircraft will be given.
The Iranian IADS is largely composed of Cold War relics originally designed and built between the 1950s and late 1960s. Arguably the most formidable of Iran's SAM systems is the Soviet built SA-5 Gammon (NATO designation: S-200) it received shortly before the collapse of the USSR. (Global Security, 2012) The Gammon variant deployed by Iran, the SA-5B (S-200VE) has a range of 200 nautical miles. NATO forces encountered a number of SA-5 missile sites in Operation Odyssey Dawn within Libya and destroyed them with relative ease through the use of cruise missiles in conjunction with electronic warfare. Though the SA-5 was highly capable SAM relative to other SAMs upon its original deployment in the late 1960s, its is now highly vulnerable to modern jamming equipment. Iran heavily relies on the S-200 for its national SAM coverage. (Air Power Australia, 2010)
(Image 3: Iranian SA-5B with launcher, retrieved through Air Power Australia)
The second main SAM operated by Iran is the 30 nautical mile capable HQ-2, a Chinese made copy of the Soviet designed SA-2 SAM system. Iran also operates the U.S supplied Hawk system it received in 1972. The Hawk variant operated by Iran has a much shorter range than the SA-5. Subsequently the Hawk would be used to target aircraft in similar ranges as the HQ-2. Iran also domestically produces a reverse engineered copy of the Hawk known as the Mersad which features moderate improvements.
The Iranian Air Force is a shadow of its former self. Prior to the Iranian Revolution in 1979, Iran had one of the best equipped Air Forces in the region. (Global Security, 2012) Despite the current poor state of the Iranian Air Force, they still pose a credible threat to the IAF in this type of scenario. The extent of the threat posed by the Iranian Air Force will be determined by the number of aircraft they can mobilize in the wake of their disabled command and control abilities (due to cyber attacks). The most formidable fighters flown by the Iranian Air Force is the F-14 and Mig 29. Both of these aircraft are outmatched by the modernized upgraded variants of the F-16 and F-15 flown by the Israeli's. Furthermore, Israeli pilots are among the best (if not the best) in the world. However, the two to three squadron Israeli strike force will be very limited in the number of air to air munitions it can carry due to: the limited number of aircraft, the weight of the 5,000 lb GBU-28 bunker busters, external fuel tanks, targeting pods, electronic jammer pods, etc. (Some aircraft will likely provide dedicated escort others will be equipped with bunker busters)
Image 4: As to be expected, Iran's most vital nuclear sites are covered by multiple layers of SAM protection in addition to being in close proximity to Iranian Air Force bases. (Image Credit: CIA)
Defeating the Iranian IADS
The IAF does not currently possess stealth aircraft of any kind. Thus, Israel must rely on other proven technologies to defeat Iran's IADS. Contrary to popular belief, the use of stealth technology is not the only method in use to circumvent an opponent's IADS. Since the Vietnam War, electronic warfare equipment has been fitted to aircraft with the purpose of jamming enemy radar's and missile systems. Since that time, electronic warfare systems have grown in sophistication and effectiveness. During the Gulf War in 1991, the prolific use of radar jamming systems and other electronic warfare equipment aided Coalition forces in defeating the Iraqi IADS. Recent developments in electronic warfare include use of cyber attacks to cripple enemy command and control abilities in addition to feeding early warning radars and sensors false information.
Israel has already demonstrated its firm understanding of electronic warfare principles to bypass an enemy IADS. In 2007 Israel launched Operation Orchard within Syrian airspace. Intelligence sources had indicated Syria was developing a nuclear reactor with North Korean assistance. IAF F-15 Ra'am (modified F-15E) and F-16 Sufa (modified F-16D block 50/52+) penetrated Syrian airspace and conducted strikes against the suspected reactor site. No Israeli aircraft were lost in the operation.
Israel managed this feat through the use of electronic jamming and cyber intrusion attempts. It is likely that the Israeli Defense Forces have comparable software to the United States in this regard. BAE systems developed a system for the United States called Suter. The following is from Aviation Week regarding Suter:
"The technology allows users to invade communications networks, see what enemy sensors see, and even take over as systems administrator so sensors can be manipulated into positions so that approaching aircraft can't be seen...The process involves locating enemy emitters with great precision and then directing data streams into them that can include false targets and misleading message algorithms." - Aviation Week, 2007
A program like Suter would allow Israeli aircraft to fly into hostile airspace and avoid detection by enemy surface to air missile sites. By necessity, Israel has some of the most skilled cyber warriors on earth. The Israeli Unit 8200 is especially renown for its cyber warfare capabilities and jointly developed the Stuxnet computer virus along with the U.S National Security Agency. (New York Times, 2012) However, there are several problems that arise in comparing the success of the Suter like program in Operation Orchard to an airstrike within Iran.
One, it its unclear exactly how long Suter is able to disorient Iranian sensors and communications. Operation Orchard involved striking one target within Syrian airspace before quickly withdrawing back to Israel. Any raid into Iran with the goal of disabling its nuclear program, would have to target multiple hardened nuclear sites to be truly effective. Breaking through the hardened facilities with current Israeli bunker busters would take repeated bombing runs preformed with near flawless airmanship over the course of days. This method would take a great deal of time compared to the relatively unfortified Syrian reactor bombed in Operation Orchard.
Second, although Suter disables ground sensors and radars, it is unclear if it is able to interfere with the senors and avionics of aircraft e.g. Iranian Air Force. Because the IAF would have to cross at least one country (e.g. Saudi Arabia) before striking targets within Iran, the possibility exists that Iranian intelligence might be able to alert its Air Force to fly combat air patrols over its critical nuclear facilities. Even if Iranian ground based radar sites are unreliable, Iranian aircraft could still intercept incoming Israeli aircraft. It is clear that other electronic warfare systems would have to be used in conjunction with Suter to disable the Iranian Defense. Israeli cyber attacks would likely target Iranian communications to mitigate this risk. However, any open cyber attack could invoke alarm among the Iranian military and likely increase Iranian military readiness. Although a sophisticated cyber attack would greatly weaken Iranian command and control abilities, it is hard to eliminate every method of communication.
Although Israel has the electronic warfare equipment needed to mitigate the threat of the SA-5 missiles, the IAF cannot comfortably destroy the SA-5 missile sites from long stand off ranges. NATO forces in Operation Odyssey Dawn made extensive use of Tomahawk cruise missiles. Israel has no direct equivalent to the Tomahawk. (Possibly for limited use of Popeye turbo cruise missiles launched from Dolphin submarines; The Dolphin is not a dedicated cruise missile submarine, missile load very limited) The longest range air to surface missile available to the Israeli strike force would be the Delilah cruise missile with a range of around 300km (officially 250km but anonymous IDF sources reported to Jane's that the missile had a 300km plus range). Even with the more optimistic range estimates, the Delilah would have a range of around 162 nautical miles, vs the SA-5B's range of 200 nautical miles. Only a limited number of Deliah's and AGM-78 anti-radiation missiles could be carried thus only key SAM sites would likely be targeted.
In summary, the IAF could likely overcome key portions of the Iranian IADS for at least short periods of time with minimal to acceptable combat losses.
Delivering the Blow
(Image 5: Israeli F-15C's (Baz) would provide armed escort for the bunker buster laden F-15E's (Ra'am)
(Image 6 Credit: Washington Post, 2012)
Both Qom and Natanz utilize a form of ultra high performance concrete (UHPC). Iran
"Iran is an earthquake zone, so its engineers have developed some of the toughest building materials in the world. Such materials could also be used to protect hidden nuclear installations from the artificial equivalent of small earthquakes, namely bunker-busting bombs." - The Economist, 2012
Commercially available U.S UHPC have stress ratings in excess of 20,000 psi. (Ahlborn, 2012) Current GBU-28 in use by Israeli's can only penetrate 20 feet of 5,000 psi rated concrete. (Expect much less penetration around 2-3 feet with 20,000 psi rated concrete, explosion would slightly widen actual penetration) Thus, dozens of GBU-28 bombs would be required to completely destroy the facility at Natanz. The GBU-28 would make short work of the 72 foot dirt mound but would experience difficultly penetrating the remaining reinforced concrete slab (reinforced roof) and subsequent barrier (8 foot thick wall). Bombs would have to be dropped at the same point repeatedly to break through one area of the barrier.
(Image 7: Natanz facility. Image Credit: Institute for Science and International Security/GeoEye, retrieved through Wired)
Both underground cascade halls at Natanz would have to be targeted as shown in the image above. Because the halls are separated into into two different buildings, more bombs will be required to completely destroy the facility. It is possible that disabling Natanz alone would require half of the IAF's 100 GBU-28 stockpile.
The GBU-28 is a combat proven and effective bunker buster against less hardened 5,000 psi rated moderately deep bunkers. That said, Fordow (Qom) is nearly invulnerable to the GBU-28. The inner enrichment hall is buried by an estimated 80-120 meters (264-396 feet) of hard rock. The only chance Israeli pilots would have in destroying Qom is to target potential weak points such as tunnel entrances or ventilation shafts. Consistently hitting targets as small as a ventilation shaft, even with the tremendous skill of Israeli pilots coupled with the use precision guided munitions, is no easy or guaranteed task. Furthermore, there are a number of relatively low cost measures to mitigate the damage done by strikes to tunnel entrances or other weak points, e.g. burster slabs, that the Iranians can pursue. Although the Fordow facility contains less operational centrifuges than Natanz, it will be considerably tougher to destroy. Even if Israel was able to succeed in destroying the majority of centrifuges at Natanz, Iran would still have remnants of its nuclear program and by some criteria, the operation would subsequently be a failure.
Israeli forces would be also constrained by the time limit allotted for the operation. The longer the operation takes in duration, the more likely Iran will be able to mount a defense of its nuclear facilities. A former member of Prime Minister Netanyahu's staff, Natan Hendel, estimated it would take Israeli two days to disable Iran's nuclear infrastructure. I do not share Mr. Hendel's optimism.
Over the course of days with relentless around the clock air strikes, Israel could destroy unhardened Iranian nuclear facilities with relative ease. However, arguably the most important facilities, Fordow and Natanz, would be extremely difficult for the IAF to destroy. Of the two facilities, Natanz would likely be given priority as it is not as heavily hardened as Fordow (Qom) and represents a greater share of Iran's operational centrifuges (Natanz has 9,000 centrifuges and Qom operates 3,000 centrifuges). In summary, even if Israel suppresses or destroy's the Iranian IADS, Israel could not extensively disable or destroy, with credible certainty, all five of the facilities listed above in a short period of time. Iran would still retain a sizable remnant of its nuclear program (around 3,000 operational centrifuges) even after the hypothetical extensive bombing campaign. Once again, individuals with expertise in nuclear development programs would be required to fully assess the damage done to the Iranian nuclear program in the wake of these hypothetical results.
Part II will examine the possibility of U.S involvement and other factors e.g. Iranian missile counterattack not discussed in Part I.
Sources
Image 8: The GBU-28 is a 19 foot long 5,000 pound dedicated bunker busting munition. The GBU-28 was used to great effect in the Gulf War against hardened Iraqi Command and Control bunkers and hardened aircraft shelters. Amazingly, the entire munition was developed in a period of just two weeks. (Image Credit: USAF)