As events accelerate with Iran’s nuclear programs – as the Chairman of the Joint Chiefs of Staff informs us Iran has passed the key threshold of possessing enough low-enriched uranium for a nuclear weapon — we may ask ourselves: Is it still possible to use kinetic force against Iran’s nuclear programs today? And is it still a realistic option?
The answer to both questions is yes. However, as with the Delay option discussed in Hit ‘em Hard, the ramifications of pursuing the kinetic course are varied, and more discouraging than not. One of the chief outcomes of reviewing these ramifications is a clear perspective on why – rights and wrongs aside – the sheer costs of pursuing a kinetic course have probably kept us from doing it so far. The time, however, is growing short to reverse Iran’s progress at a cost with any real political acceptability – even for a US administration of a different character. As we will see, in examining the features of kinetic attack at different objective levels, there are two important chains of events that will dictate the level of will we must possess: Iran’s progress toward taking her nuclear reactors critical, and her progress in improving her air defenses.
In earlier discussions, we broke our options against Iran’s nuclear program down into Delay, Reverse, and Prevent. Hit ‘em Hard was a discussion of the Delay option, looking at sanctions and embargo. This post will focus on the kinetic attack approach associated with “reversing” Iran’s progress to date – destroying facilities and materials, forcing her to reconstitute them. A follow-on post will address “preventing” Iran from acquiring nuclear weapons altogether.
As we will see, it quickly becomes pointless to try to look at these options – Reverse and Prevent — in isolation. Reversal is only possible through kinetic attacks of some kind; and once kinetic force is in play, its inherent implications make it unlikely in the extreme that any version of the Reverse option can unfold without escalating consequences. That said, an attempt to reverse Iran’s progress, at least to some minimum level, is the only option Israel has, and for this reason, if for no other, it is important to consider the possibility of attempting the Reverse option, per se.
One administrative note before proceeding. I have tried to keep this discussion from delving excessively into the technical; but also to convey an operational-level flavor – a planner’s-eye view – of what is involved. This took some work. A career intelligence officer is far too likely to go off on tangents about the target discrimination capability of the S-300’s BIG BIRD radar, the kinetic prowess of the BLU-113 warhead, and the comparative maneuverability of the F-16 versus the MiG-29. What I would rather readers come away with is an informed impression of the “major muscle movements” – the big outlines – of the operational requirements for executing the kind of strike in question, and how those requirements end up dictating the ultimate character of the effort.
I include a couple of maps, and you will find hyperlinks in the text to key references, and as back up for certain assertions. I have not put in links for all the weapon systems referenced in the text, knowing that intelligent readers of the OC blog can do web searches for any further information they desire. I do not provide a comprehensive list of the nuclear-related facilities in Iran, or a description of the nuclear enrichment or weapons production process, because very good ones are available elsewhere. The Iran nuclear website of the Institute for Science and International Security (ISIS) is a good place to start – and one that readers can feel intellectually virtuous about patronizing, given that its authors, while they labor to report accurately – and indeed, they are convinced that Iran is very close to achieving a nuclear weapons capability — are firmly opposed to kinetic strikes on Iran.
I am building a reference list for my Features page, which will be of interest to those who want to do further reading. Look for that in the next week. I have verified facts and bounced concepts off of the excellent work being done by others in cyberspace, but I take responsibility for anything that smells funny here. With this in mind, here we go.
In its simplest form, the concept of reversing Iran’s progress with her nuclear programs to date envisions conducting air and missile strikes on her facilities. As with the Delay option, we must first ask ourselves what exactly we hope to achieve. Do we want to interfere with key aspects of the programs, such as the centrifuges already installed at Natanz for ongoing uranium enrichment? We could expect doing this to set Iran back for several months, at least, and very probably – almost certainly — more than a year. Given the assessment that Iran already has enough low-enriched uranium (LEU) on-hand for a weapon, we would need to approach this goal understanding that it is not designed to prevent Iran from reacquiring centrifuge cascades, including the ability to enrich the LEU she already has to higher levels.
Do we, then, want to “take out” the enriched uranium too? This objective carries the human and political cost of releasing contaminants into the atmosphere. Beyond this, should our approach be to kill as much of the program as possible: research and processing facilities, stocks on hand (of missiles and rockets as well as nuclear material), key personnel? This is an operation of much larger scope. It is not infeasible for US forces, although it is beyond Israel’s capabilities. This goal could produce delays for Iran of at least three years, and almost certainly more, to reconstitute all her programs and stocks – missiles/rockets as well as uranium enrichment, and her pre-operational reactors — to current levels of progress and scope. The rapidity of reconstitution would depend heavily on how much outside support Iran received.
Basically, the Reverse option breaks down into two suboptions: a shorter reverse, involving less destruction, or a longer reverse, involving more. Evaluating these options includes considering what is necessary to bring them off – and, since they involve military attack, considering what overall effect they are likely to have on Iran’s national will and intentions.
In the context of our discussion so far, there are two important reasons why we would want to spend much time on the less-destructive, shorter-Reverse option. First, it is the option most people unconsciously have in mind when they talk about “surgical strikes” on Iran’s nuclear facilities. And second, it is the level of attack Israel could bring off. American forces are capable of a much broader scope of attack, but if Israel decides it is necessary to attack Iran’s facilities, the shorter-Reverse option is the one most representative of what she can achieve.
A key factor in considering this shorter-Reverse option is that Iran has made substantial progress since 2003 at the handful of primary facilities that would be struck, to achieve the goal of interdicting “principal nodes” for at least 6-12 months. Not only has a lot of construction been completed, both underground and above, but tunneling for suspect purposes is well underway at the uranium conversion facility at Esfahan, and the uranium enrichment facility at Natanz. This progress is both good and bad news. On the positive side, attacks mounted now could effectively reverse substantial work already completed. In the “less good” column, the more underground damage that is contemplated, and the more of the completed facilities there is to destroy, the more “thump” is required per target. Given the brief, probably “single-shot” effort Israel would be able to mount, this means fewer target complexes, and more aircraft and bombs per complex.
Moreover, with over 1000kg of low-enriched uranium (LEU) now stockpiled, a strike concept must accept the likelihood of radioactive and chemical release with kinetic attack on these materials – or, try to avoid key aimpoints at Natanz and accept a much lower-payoff operation. Destruction of the LEU by kinetic weapon poses a risk of radioactive contamination in the area, and a significant risk of lethal chemical contamination from the hydrofluoric acid that would form with release of uranium hexafluoride (UF6) into the atmosphere. Although most predictions in advocacy writing about the geographic spread of this contamination are overblown, the most sober and accurate estimate must still make this possibility a significant decision factor for any strike on the facility. The more LEU there is in storage at Natanz, as enrichment progresses with time, the bigger this consequence of a strike gets.
Israel’s most significant overall constraint by far is that she will not be able to mount sustained, successive air attacks on the Iranian targets. She will have the option of sequenced attacks in a single strike package – e.g., pairs of aircraft restriking a target complex in sequence – and that can be important to success against underground/hardened targets. But she can only plan this sequencing over a very short period of time, probably minutes. The US standard of striking once, performing battle damage assessment from carefully timed surveillance, and striking again – this well-worn process is not available to Israel for the Iran problem. She will almost certainly have to “get in and get out” of her whole profile in Iran in a matter of 1-1.5 hours at the most, not only because of Iran’s air defenses but because any quiescence she can count on in the airspace of other nations will end quickly. Turkey might tacitly allow a single-day strike to access Iran through her airspace, but the Israelis cannot count on such permission extending beyond the news cycle.
(That said, the Israeli Air Force probably has strike packages built around both contingencies: more extended, explicit airspace access in an adjacent nation, and less. Israel is capable of multi-day strike operations with her own resources; the limiting factor is quiescent airspace access. We should expect Israel to have planned for longer airspace access, which would give her slightly broader options for target selection. The expansion of those options is, I note, limited itself by the fact that Iran would be alerted to all follow-on strikes, and present a harder overall target. We should equally expect the IAF to be fully ready to execute the most likely course of action, and strike fewer targets, harder, in the brief time she can expect a neighboring state to let her forces operate unhindered in its skies.)
Targets and Effects
With these constraints in mind for the most basic, limited Reverse strike, let us briefly review the priority targets. We will do that inelegantly, out of strike sequence, because it is high time we took our first look at the nuclear program targets. They will not be the first ones it is necessary to deal with in building the strike package, but they are the “main effort” in this scenario. As we will see, with a “Strike on a Budget,” other factors are likely to winnow the list of desirable targets down further; but these are the main ones planners will want to hit.
Opponents of military strikes on Iran like to throw out numbers like “100 important sites” and “1200 potential sites” in characterizing the scope of the targeting problem. However, although there are legitimate concerns about the completeness of our knowledge at some secondary sites (and even the primary ones), it would be specious to argue that we could not set Iran’s programs back by at least half a year, and almost certainly more, with comprehensive destruction of two main complexes: the uranium enrichment facilities at Natanz, and the Nuclear Technology Center at Esfahan. The loss of these two facilities would generate a bottleneck in Iran’s capability to independently convert uranium to uranium hexafluoride gas (UF6 – done at Esfahan), and enrich it to low-enrichment levels (at Natanz), whether to fuel a reactor, or as a precursor to higher-level enrichment.
If possible, additional priority targets would be the heavy water reactor under construction at Arak (a source of plutonium once in operation), and the Tehran Nuclear Research Center, where several key research facilities are located. Striking the light water reactor at Bushehr is less directly relevant to a nuclear weapons program, and would also present geographic challenges to an IAF strike package, which are likely to render it too costly relative to the benefit – at least from an air strike perspective. An alternative (for either an Israeli or a US attack) would be the use of special forces to destroy or disable the Bushehr reactor. Its location on the coast in the Persian Gulf adds to the feasibility of this option.
Additional potential target complexes include a missile and centrifuge production facility (the “7th of Tir Industries” site) south of Esfahan, and the Kalaye Electric centrifuge R&D/assembly facility in Tehran. As we will see throughout this discussion, Israel will face uncompromising tradeoffs in putting together a strike package, and targets like these may not be high enough priority for a single-shot strike. The Natanz and Esfahan facilities combined would require the striking of at least three dozen aimpoints, many of them more than once, and a handful of them multiple times with the heaviest weapons. Although modern weaponry would enable Israel to re-execute the 1981 strike on Osirak with less than half of the number of aircraft she used for that attack, either Natanz or Esfahan, by itself, is several times more complex a target installation than the Osirak reactor. Both targets will require dozens of weapons and multiple strike passes. Effective attacks on the targets in Tehran would also involve dozens of aimpoints, with similar operational concerns.
More difficult than hitting these priority facilities and their well-characterized features would be reliably interdicting Iran’s ability to enrich uranium to high (weapons-grade) levels using centrifuge processing. Since high-enrichment processing is prohibited by the Nonproliferation Treaty to which Iran is a signatory, Iran has not disclosed any operational activities in this regard to the IAEA. Iran’s centrifuge development and manufacturing program would be set back by comprehensive strikes at the Pilot Fuel Enrichment Plant at Natanz (separate from the underground operational enrichment facility), the 7th of Tir site south of Esfahan, and possibly the Kalaye Electric site in Tehran; but the extent of any existing preparations to undertake high-enrichment processing, at an undeclared facility, is not known.
We do know that Iran has dug tunnel complexes at both Esfahan and Natanz, with tunnel work at the former being first detected in 2004. IAEA inspectors were allowed to visit the empty tunnels at Esfahan in 2004, but there have been no follow-on visits to the tunnels at Esfahan, or any admission to the tunnels at Natanz (first observed in 2007). Iran has stated that the tunnels are for storage. This is unlikely to be all they are for (the IAEA visitors to Esfahan’s tunnels did not think so), particularly given the scope of the tunneling at Natanz, which is where the growing stockpile of LEU is kept, nominally under IAEA supervision. There is not enough positive information yet to definitively characterize the tunneling activity at either site, especially Natanz. If the Natanz tunnels lead to a major underground complex that might be intended to support high-enrichment processing, we could expect to see some activity in overhead imagery – certainly as early as this year — that tips us to arrangements for features like electrical power and exhaust.
Since the tunnels are adjacent to the main target complexes anyway, the operational cost of hitting them while in the vicinity is not high – although doing so is not a reliable guarantee of interdicting specifically enrichment-related activity. We may note further that Iran’s existing 1000kg+ of LEU, stored under IAEA supervision at Natanz, could be destroyed in a facility strike, and lengthen any setback imposed by the loss of currently operational processing functions at Esfahan and Natanz. As discussed above, however, kinetic attack on the LEU poses a significant risk of release of chemical and radiological contaminants.
The bottom line, on interrupting or reversing any progress Iran has made on preparing to enrich uranium to higher levels, is that the shorter-Reverse approach cannot guarantee a comprehensive result. The history of unexpected “finds” in Iran related to her nuclear program, Iran’s obvious attempts to hide them, and her persistent refusal to act more transparently and cooperatively in fulfilling her NPT obligations, all indicate that Tehran remains motivated to hide and deceive. We may deduce that Iran has not been rich enough since 2003, and has been watched too closely, to have developed a very advanced, secret — but entirely undetected — program, one operated in parallel with her known efforts. This is my own opinion. But we cannot be absolutely certain. When knowledgeable commentators conclude that military strikes are not “worth it,” it is generally the absence of a guarantee on this head that they are ultimately referring to.
That said, the loss of functionality at Natanz and Esfahan would still represent a significant setback, requiring time and money to overcome. As for the capability to deal such a blow: Israel would, with no constraints on time over target, or target revisit options, possess the skills and weapons to attack any of the targets listed here. But for an IAF strike, the operational constraints realistically govern everything else. Israel may make the choice of limiting her strike package to central and northern Iran, with the highest-payoff target complexes being Natanz, Esfahan, Arak, and the Tehran Nuclear Research Center. The additional force packaging that would be required to get bombers over Bushehr, inconveniently distant from the other priority targets, militates against Israel including it in a single-shot airstrike. Targets in Tehran’s urban area, while desirable to hit if possible, may not be high enough payoff for entering the Tehran SAM threat envelope, even with standoff attack profiles. A harder “thump” administered to the top two target complexes – with increased certainty of achieving the intended destructive effects – may be considered preferable.
A last note about striking the reactors. Before they are fueled, they can be destroyed to inoperability with no concerns about toxin release. Once they are fueled – as Iran says the Bushehr reactor will be this year – kinetic attacks pose a risk of toxin release from the processed uranium, similar to what they pose at a UF6 storage site. And of course, once the reactor is taken critical, controlling its shutdown, or mitigating the consequences of bombing it from the air, becomes a delicate planning and execution problem. It is inaccurate to say that it cannot conceivably be done; but the cost of doing it with a low risk of environmental exposure increases considerably. We can safely say that targeting planners would resist trying to bring it off in an abbreviated, single-shot airstrike.
The Strike and Iran’s Air Defenses
It is in this targeting context that Israel would plan a comprehensive strike package. For any airstrike, the first priority in time is the target nation’s air defenses. For the most likely one-day attack plan, Israel will have to suppress and defeat, but not necessarily destroy, Iran’s air defenses, probably toward the northwest from Tehran, and extending to Natanz and Esfahan, the last in the center of the country. Turkish airspace is the most probable approach route for the IAF. Its utility is independent of America’s political posture. If Jerusalem does not have Washington’s implicit OK beforehand, US assets are probably the main ones the IAF needs to worry about, between Israel and Iran; and our aircraft operate less autonomously in Turkey than in Iraq, Kuwait, or the Persian Gulf (southern approach routes from Jordan or Saudi Arabia). For an operation of this kind, even non-lethal interference could well knock the IAF off a very tight timeline.
Iran does not yet have a modern, integrated national air defense system. Suppressing Iran’s current air defenses would, in practical terms, be a matter primarily of defeating fighter aircraft reaction, and rendering ineffective the relatively old surface-to-air missiles (SAMs) currently deployed for area and site defense. This is not an easy task, but under current conditions it is a feasible one. The Air Defense figure shows the locations of major air bases and area-defense SAM sites. Tehran is the most heavily defended area, and would likely require more defensive escort per bomber than aircraft groups headed to Natanz and Esfahan. The primary threat bases along the latter route are the fighter bases at Tabriz, Hamadan, and Dezful, all of which are frontline, daily-operational bases.
Virtually all the fighters encountered by a strike force coming from Turkey, before the approach to Esfahan, would be older F-4 and F-5 variant aircraft, whose only advantages against Israeli F-15s and F-16s would be the short flight profiles they could operate on, and their numbers. The IAF escort fighters are more maneuverable and would be better operated, but would be performing very long missions (a fuel issue for intensive maneuvers), and would have less local redundancy than the IRIAF’s less-capable forces.
The air base at Esfahan would present the greatest overall air threat to mission success, against the Natanz and Esfahan facilities, with its two squadrons of F-14As and three squadrons of Chinese-built F-7s (older MiG equivalent) fighters. Neither is a modern aircraft, or the equal of the IAF’s frontline fighters, but Esfahan would be able to put at least five or six fighter pairs up – possibly more — over the period of the IAF’s approach and on-target operations at Esfahan and Natanz. And unlike the bases further northwest, Esfahan would likely have the advantage of prior notification of the strike wave, even if only by voice communications.
Tehran is protected by the country’s most thoroughly layered SAM coverage, and by Iran’s only MiG-29 squadron, at Mehrabad (the MiG-29s, originally Saddam’s, escaped from Iraq in January 1991, and never went back). The MiG-29 is Iran’s most modern fighter, and while its numbers are few in the IRIAF (and there is some question about Iranian pilots’ proficiency), it combines with the longer-range fixed SAM systems that surround Tehran, and the overlapping radar coverage, to make Tehran a comparatively challenging target area. If the IRIAF was able to launch its electronic warfare or reconnaissance aircraft, based at Mehrabad, during an Israeli strike, they would also be most likely to have an impact on the course of events in the Tehran area. (There is the possibility, of course, that Iran would launch them not into combat but to get them to safety, since she only has one each of these important platforms.) As mentioned above, the decision to include Tehran targets in the strike operation would involve increased force packaging: probably splitting the attack forces and providing separate escort and support services.
Meanwhile, a few more observations may be made about Iran’s air defenses. Her early warning capabilities are comparatively primitive still. There are holes in her long-range early warning radar coverage, which is based on a half dozen JY-14 radars purchased from China in the late 1990s. The JY-14 is moderately capable but outdated in terms of countermeasure resistance and processing capability. The first wave of IAF attackers would have a good chance of being able to exploit gaps in coverage.
This advantage is amplified by the fact that Iran does not have a true “IADS,” or integrated air defense system, through which radar detections from multiple systems can be centrally coordinated, and optimum allocation of SAM and fighter assets directed, using a comprehensive picture of the air situation. While it lasts, this shortfall is a very favorable condition for an Israeli strike force, which would thus not face an air defense system anticipating it, and handing it off from one element or sector to another, but rather a series of individual fighter bases and SAM operators, all needing orientation and analysis time before making decisions and responding effectively.
An IAF strike could be able to complicate Iran’s air defense reaction further by using the western mountains to mask its approach. The Sahand mountains near the extreme northwest border with Turkey, and the long Zagros chain on Iran’s western border, combine to offer this very real option. (At least one analyst in the public domain estimates that the Zagros Mountains effectively obscure the target acquisition capability of the SA-5 SQUARE PAIR radar at Esfahan through its entire southwest quadrant – a very advantageous possibility, if that assessment is valid.) A tradeoff with this approach would be fuel expenditure, since the strike force would have to hug the mountain terrain to remain undetected until making a rapid “push” to the east, to strike the nuclear facility targets. The impossibility of refueling inside Iranian airspace is a constraint on this option.
Almost the entire western approach to Tehran, and the Natanz/Esfahan target areas, is covered by the target acquisition radars of the fixed-site SAMs that guard the central corridor of northern Iran. These include a dedicated SA-5 GAMMON in the vicinity of Esfahan, and the SA-5s, Hawks (US), and HQ-2s (Chinese variant of the SA-2) that guard Tehran. In this part of the country, east of the Zagros Mountain chain, Iran achieves comprehensive, overlapping airspace coverage with her TA radars. The SA-5 has the greatest missile intercept range – up to 88 nautical miles (160km/100 statute miles) – but all the fixed-site SAMs use 40-year-old technology, and Israel possesses the skills and capabilities to defeat these systems.
At individual target sites, the IAF will be met by the radars and missiles of mobile point-defense SAMs, of which the most modern is the Russian TOR-M1, or SA-15, backed by the older SA-6. The SA-15 and SA-6 present a respectable challenge at the target areas because of mobility and numbers, although the IAF is equipped to defeat them, with sufficient alertness and proficiency. In combination, the fixed-site and point-defense SAMs could well complicate the IAF’s force protection problem enough to produce at least one kill, and perhaps more, for the Iranians.
The IAF is likely to need at least some munitions delivery directly over the targets, to achieve ground penetration and perhaps ensure timed sequencing. A strike entirely accomplished with stand-off weapons would not inflict the level of damage required to make it worthwhile. There will be a lot going on in the highly intense and vulnerable seconds a fighter-bomber pair spends over its target. EW and fighter escorts will run interference for the bombers – the bombing aircraft will be wholly dependent on their escorts once they start their target runs – but in a single-shot mission, the ultimate priority is likely to be delivering the ordnance, even if the escorts have not been able to guarantee perfectly favorable conditions over-target.
Air Defense Improvements for Iran
These are the features of Iran’s air defenses in place today. But Iran is trying hard to improve them, and build more formidable defenses against air attack. Tehran this month announced the designation of air defense as a separate armed forces command, highlighting the importance being assigned to this military discipline. The relatively quiescent air defense environment Iran currently presents would become prohibitive – literally – for the IAF acting alone, if Iran achieved a true integrated air defense capability, and the long-desired milestone of fielding the Russian S-300P-variant SAM system.
Russia continues to deny Tehran’s latest claims that S-300 components have been delivered, but once they have been, and have been fielded with the operating forces, the S-300P-series SAM will be a game-changer. The S-300P-series SAM comes with radars that will give Iran increased range of coverage, dramatically improved low-altitude coverage, and countermeasure-resistant features. The S-300P’s fire control system would allow much better target discrimination, and vastly improved tracking in high-volume situations – and reportedly is user-friendly and easy to learn. The missile Iran is likely to get can intercept out to 110NM (208km/166 statute miles) and has effective countermeasure-resistant features. It is important not to miss a key consequence of this improved missile range: aircraft such as electronic countermeasures escorts may well have to enter the missile’s threat envelope to be effective.
Israel’s modern air capabilities are not a poor match, by any means, for the S-300P in the variant Iran is likely to get. However, even without the incorporation of the S-300 into a true IADS, its implementation in Iran’s forces would singlehandedly change her air defense profile, making any contemplated attacks likely to be significantly more costly, both in force packaging and expected losses. Assembling the communications and IT backbone of a genuine IADS, and integrating the S-300 into it, would dramatically increase Iran’s ability to sort and discriminate a local air picture. The political calculus of decision for any attacker would change with either development. The US, which could overwhelm Iran’s defenses with sheer numbers, would still be likely to lose more assets than Americans have had to face losing in decades – and Israel does not have the force depth to reliably punch through an optimally-deployed, IADS-integrated S-300 network at all.
As we see in this brief survey, conditions at the potential target sites, and with Iran’s air defenses, still make an Israeli strike feasible, on the single-shot basis the IAF is likely to have. To the question whether existing, conventional air-to-ground weapons can put the requisite thump on the facilities at the main nuclear program targets, the answer is yes. There is no need to use nuclear warheads on the targets in Iran, to achieve a useful level of destruction. The shorter-Reverse option, in particular, we have defined as setting Iran’s programs back by a factor of at least six months. The objective of this level of operation is not, and cannot be, to permanently disable Iran from any capacity to pursue nuclear technology or weapons. The use of a nuclear weapon to attack an Iranian facility represents an expenditure of political capital wildly out of proportion to the objective sought, and cannot be justified. Conventional warheads will do the desired damage.
Israel has acquired 5000-lb, “bunker-busting” GBU-28s from the US, and would undoubtedly use them on the underground uranium enrichment facility at Natanz. 2000-lb and smaller weapons would be sufficient for most of the other features at Natanz, and in fact for most of the aimpoints at all the major targets: Esfahan, the Tehran Nuclear Research Center, Arak. The most challenging target elements would be the underground ones. A good analysis done at MIT in 2006 may be referenced for the weapons likely to achieve the requisite “thump” on the underground enrichment facility at Natanz. Although it is likely that substantial damage would be done by even fewer BLU-113 warheads than suggested in that analysis, Israel has enough to “overkill” the target for assurance, and may deem that the best option given the high cost of the overall operation.
On the tunnels at Esfahan and Natanz, information is scarce on their extent, and on the character and location of what is inside them. I note, however, that for the purpose of setting Iran’s programs back, it is not necessary to precisely eliminate a list of discrete items that may be in the tunnels. It is equally useful to bury them and/or do damage to them. Make Iran dig back into them – and very likely lose at least some of what has been achieved inside them (e.g., hardened storage, or a facility for high-level uranium enrichment). Particularly for a single-shot strike, this is a worthwhile targeting approach. Attacking the tunnels, however, implies a tradeoff with other potential priorities. Intensive attacks on the tunnels – and there is no point in non-intensive ones — would cut into force availability for additional target complexes, such as Tehran and Arak.
As we see here, Israel’s options are either heavily constrained at the outset (size of force, approach route, number of shots at the targets), or involve tradeoffs: of fuel with stealth, of target saturation with more targets struck. Only Israel’s leaders know if they will prize hitting more targets over doing greater damage to fewer targets — and probably reducing the risk of losing pilots and aircraft. Only the IAF’s senior commanders know what risks they are prepared to take to achieve stealth – or how much they will trust standoff weapons, and reduce vulnerable time over target for their bombers.
At the moment, Iran’s air defenses are not a show-stopper, either militarily or politically. They may become that. Under current conditions, however, it is conceivable for Israel to do a useful level of damage to a key, minimal target set, without paying too high a military price during the strike.
The question that is begged, however, is what the overall cost of such a strike would be, in the consequences of a reaction by Iran. There is nothing inherent in the shorter-Reverse option that would deter or inhibit Iran from lashing out in a variety of ways. Israel is not capable of administering such deterrent measures through conventional military action. As we will see in the next installment, the potential for Iran to react in lethal or destabilizing ways is as important to address as the nuclear facilities themselves.