The Jerusalem Institute for Strategy and Security

The key to avoiding a Saudi-style debacle in Israel is prior intelligence and seamless early warning systems.

In the dark of night, during the predawn hours of September 14, 2019, a swarm of delta-winged unmanned aerial vehicles (UAVs), their two-cylinder gasoline engines buzzing noisily, approached the giant oil processing plant in Abqaiq, Saudi Arabia. Flying “on the deck” at low altitude (only several meters above ground), the swarm remained undetected until, close to its target, it climbed briefly only to dive down almost vertically towards the rows of giant liquid natural gas (LNG) tanks. Each UAV zeroed-in on its predetermined target, locked on it via its night vision “eye,” then crashed into it, creating a jagged hole that turned the tank into a useless hunk of metal.

At the same time, a gaggle of swifter, jet-powered aerial vehicles sneaked its way towards the Khurais oil field, hugging the ground all the way to their target. Some UAVs did not reach their destination and crashed into the desert, either because they ran out of fuel or because of malfunctions. Those that did reach Khurais selected their pre-programmed targets, destroying two key facilities in the oil field and creating giant fires that sent billows of black smoke all the way to the stratosphere.

With both the Khurais oil field and the Abqaiq oil processing plants out of commission, Saudi Arabia’s oil output was cut by more than 50%. This was the most devastating air strike on the Middle East oil industry since the Iran-Iraq war of the 1980s. This was also a surprise attack resembling in audacity, if not in scale, the 1941 surprise Japanese attack on Pearl Harbor. In a sense, September 2019 might be remembered as Saudi Arabia’s “Black September.”

While the attack triggered a temporary surge in oil prices, its longer-term effects on the global economy were muted by the US opening its oil reserves to the market and by an energetic recovery operation by Aramco, the Saudi Arabia state-owned oil company, which worked 24/7 to repair the damage and bring both facilities back to full production in short order.

The long-term implications of these landmark attacks depend on several questions, including who did it and how? And no less puzzling, why didn’t Saudi Arabia detect the incoming attacking weapons, not to speak of shooting them down? The information at hand at this time is insufficient to provide full and satisfactory answers, but some possible answers can be sketched-out, and the remaining puzzles outlined.

Technical and Operational Aspects

It is now known that the attacking force comprised a total of 25 air vehicles. 18 propeller-driven delta wing vehicles attacked Abqaiq of which at least 17 (94%) struck their targets. Another flight of seven jet-propelled vehicles attacked Khurais, of which only four (less than 60%) struck their targets, the rest crashing in the surrounding desert. That each plant was targeted by a different type of weapon seems significant, although the significance is not yet clear. Satellite images of Saudi Arabia from the morning after show five large smoke pillars, the largest obviously from Abqiaq and the rest from four locations aligned from southwest to the southeast. Closer inspection shows that the smoke pillars came from controlled fires, not from the drone attacks. As far as is known, no other target in Saudi Arabia was hit that night.

Images of the damage in Abqaiq show that it was hit with a dazzling accuracy. Most of the huge, spherical liquid natural gas (LNG) tanks in that facility show a single gaping hole at the same spot. Obviously, each tank was individually acquired and struck by a single UAV. No tank shows more than one hole. Such sterling accuracy was somewhat lacking in the attack of the nearby processing towers. One of them was struck three times, another was struck once, and the rest remained untouched. This kind of pinpoint precision probably goes beyond what the GPS system could provide and may involve active optical self-homing, using pattern recognition software. This might explain the disparity between the perfect score on simply shaped spherical tanks and the less than perfect score on the more geometrically complex shapes of the processing towers, surrounded as they were by mazes of piping. While manual homing by remotely located human operators cannot be precluded, it is less plausible than autonomous homing. If so, this indicates a level of technical sophistication on par with the major industrial powers.

Another outstanding feature of the attack was its speed. Whatever real time visual evidence that is now available from the attack comes from onlooker smartphones and from the security cameras within Abqaiq. The impression is that the attack was quite concentrated. All video clips show many fires burning at the same time. One short clip from an on-site security camera shows a hit in an LNG tank while three others are already burning. Had the attack been protracted, one would expect clear evidence of a protracted series of explosions. The impression is that all hits were achieved in minutes, perhaps no more than one minute. This means that the attacking fleet of UAVs was bunched up into a swarm, reaching the target almost simultaneously. Propeller-driven UAVs fly at speeds of up to 200 kilometers per hour. If the attack lasted one minute, that would mean that the UAV formation was spread along just three kilometers – a remarkably tight formation after a long flight from wherever the swarm took off.

Yet another outstanding feature of the attack is the absence of any casualties. The Abqaiq oil processing facility abuts the dense population center of Abqaiq City. No casualties were reported either in the processing facility or in the city itself. Moreover, no damage was recorded in Abaiq City – not even broken windows. From the photographic record of the damaged installations, it seems that the attacking vehicles carried very small warheads, or – more likely – no warheads at all, inflicting the damage by kinetic force of impact rather than by explosions. Obviously, casualties would have exacerbated the impact of the attack, generating demands for retribution. The lack of casualties was to Iran’s advantage. One can only appreciate the cool, calibrated planning of the Iranian operators.

With no evidence of more delta-wing UAVs crashing somewhere in the open desert, it seems that the reliability of the propeller-driven, delta-wing vehicle is impressive.    The reliability of the jet-driven machines seems less impressive, with more than 40% of the attacking force failing to reach its target. This may indicate that the jet-propelled vehicle is less mature than the propeller-driven one, for which we have few clues regarding their provenance. The jet-propelled UAV is definitely identified as a new cruise missile, unveiled by the Houthis in June 2019 under the appellation “Quds 1.” It is a somewhat bizarre looking vehicle, with a pylon-mounted, small Czech designed jet engine protruding from its back, with wings and tails resembling the Iranian “Soumar” land-attack cruise missile, although the “Quds 1” seems to be much smaller. (The Czech company has denied any involvement, claiming that the displayed units were crude copies of their product). It is hardly conceivable that such a complex vehicle could be developed by the Houthis. In all likelihood, it is of Iranian design. And indeed, a US analyst (Fabian Hinz in The Arms Control Wonk) quickly dug up a photograph of a similar looking wind tunnel model displayed in a February 2018 exhibition in Tehran. The first full-sized operational “Quds 1” was seen in June 2019 in Yemen, barely 14 months later. This may imply that the missile’s development cycle was hastened for the sake of early deployment, sacrificing reliability on the way.

The provenance of the delta-wing machine is more obscure. Significantly, no such vehicle was ever seen in Yemen. At the same time, a very similar machine – perhaps an identical one – popped up briefly in Iran in late 2014. An article in Mashregh News described 10 types of Iranian suicide UAVs. One of them, dubbed “Toufan,” is a delta-wing machine described with the capability to be homed into the target via an optical sensor. While the 2014 “Toufan” is described by Mashregh News as a short-range, short-duration vehicle, the similar machine that hit Abqaiq almost five years later could be an evolved model with extended range and self-homing capability. The commonality of the low radar signature, delta wings and optical homing between the “Toufan” and the unnamed attackers of Abqaiq could hardly be a coincidence. The five years elapsing between the first appearance of the “Toufan” in Tehran and its 2019 reemergence in Saudi Arabia may have been used to improve reliability. The disparity in reliability between the two designs may thus reflect different levels of maturity.

The Iranians have strived ever since the beginning of their intervention in Yemen to create a degree of deniability to avoid UN censure for breaking its mandated arms embargo on Yemen. Thus, all the weapons used by the Houthis are described as “of Yemeni origin” even when they are Siamese twins of the Iranian originals. For the September 14 attack, the Iranians went at some length to ensure deniability. As described above, the full-scale, operational Quds 1 has been seen to-date only in Yemen. To build up its “Yemeni” provenance, it was used since June 2019 for a series of attacks on nearby Saudi towns, leaving behind telltale debris. This allowed the Houthis to take full credit for the Sept 14 attacks, absolving the Iranians from any overt responsibility or connection to it. The question from where the attack originated is still open at this time. There is some circumstantial evidence that attack did not come from the direction of Yemen but rather from somewhere northeast of Saudi Arabia. One piece of evidence is the alignment of the holes punched into the spherical tanks in Abqaiq. They are all facing north by west, not south by east as would be expected if the attack came from Yemen. Clear evidence of a non-Yemeni origin of the attack is still lacking. For example, the location of the three “Quds 1” missiles that “fell short” could have indicated the direction from which the attack arrived. But Saudi authorities have not yet released this information. In its post-attack press conference, the Saudi military stated that they have proof that the attack did not originate in Yemen and promised to provide the evidence to the UN commission of experts that has been monitoring the war since September 2017. If so, the commission’s grindingly slow rate of doing business ensures that when the evidence surfaces, it will be quite obsolete.

The identification of the Quds 1 jet engine’s Czech origin provides enough information to reconstruct the missile’s dimensions, weight and fuel load. Simple calculation indicates that if launched from Houthi territory, Khurais would be at the extreme end range of the Quds 1, if not beyond it. The slower delta-wing UAVs would have to fly for more than eight hours to traverse the 1,000+ km. distance from Houthiland to Abqaiq while crossing mountain ranges, all this without being observed. This makes Yemen as the point of origin possible but less plausible.

However, the Iranian campaign of deniability is incomplete. There was no effort to build up a case of “Yemeni origin” for the delta-wing UAV. This vehicle was never seen in Yemen – in fact, not even after the attack – and it carries no Houthi “nom de plume.” The reason for this lacuna in an otherwise flawless planning of the operation remains obscure. Still, it is clear that of the two oil installations struck on the night of Sept. 14, it was Abqaiq (which was targeted by the delta-winged UAVs) that was clearly the main objective of the Irani an operation – its Schwerepunkt so to speak.

Abquiq produces and processes 5.5 million barrels of oil per day, a full 53% of Saudi Arabia’s daily oil exports. Khurais, on the other hand produces “only” 1.5 million barrels of oil per day, just 15% of the Kingdom’s oil exports. It would be reasonable for the Iranian planner to use the more reliable and stealthier delta-wing vehicle against Abqaiq, the main target. Perhaps the reason why Khurais was struck at all was to create a diversion, using the less reliable but clearly identifiable “Houthi” weapons in order to divert blame from Iran and to build the credibility of a false “Yemenite origin” of both attacks.

Another remarkable feature of the attack is the complete lack of early detection. The two formations of incoming threats – each following a different flight path to its assigned target – was neither detected by Saudi Arabia’s air traffic control nor by its air defense sensors. Neither were they detected by the US air control systems deployed in the area, nor by US satellites. One YouTube video clip from Kuwait purports to show a jet-propelled object crossing its airspace shortly before the attack, but it was taken by a security camera, not by Kuwait’s air defense assets. In his briefing to the press, the spokesperson of the Saudi armed forces screened a video from a security camera showing one of the low-flying raiders crossing its field of view. This however was a perimeter security camera which was not connected to Saudi air defenses. The absence of early detection indicates that the attacking swarms flew either outside the range of Saudi and US radars, or below their horizons, or both. This in turn indicates that the attack’s planners had before them a detailed picture of Saudi and US early warning systems in the area, their locations and capabilities, allowing them to route their UAVs and cruise missile around and below their detection volumes. This indicates good spycraft. According to the Houthi announcement after the attack, it was preceded by a “careful intelligence operation, prior monitoring and cooperation from honorable and freedom-seeking people within the (Saudi) kingdom.” One however should be careful here. The Iranians have a clear interest in fomenting discord in Saudi Arabia, and as such the claim of a local fifth column is self-serving. Yet the prospect of local espionage in exchange for money is not implausible.

Hand in hand with the absence of early detection comes the total passivity of Saudi Arabia’s air and missile defenses. This however should be less than surprising to veteran watchers of the war in Yemen. The Saudi-led coalition intervention in Yemen in 2015 brought with it a protracted and still-ongoing missile and rocket attacks on coalition forces inside Yemen and on Saudi cities, towns, military bases and oil installations inside Saudi territory. Saudi Arabia’s air and missile defense has managed to destroy some of the incoming threats, although the exact numbers and rate of success has not been released to date. (According to the Saudi army spokesperson at the post-attack press conference, Saudi defenses have destroyed “almost 200 ballistic missiles and 254 UAVs”.) That the Saudi Patriot air and missile defense systems have been scoring some successes is indicated by fact that the Houthi’s began attacking the Patriot batteries themselves, using low and slow “Kasif 2” propeller-driven UAVs. Since the beginning of 2019, the bulk of the attacks on Saudi targets have been with UAVs and cruise missiles, not rockets and ballistic missiles. Evidently, the Houthis and their Iranian sponsors have discovered a chink in Saudi Arabia’s armor. Air and missile defense radars are configured to detect high-flying threats. Since they are not required to detect ground-hugging objects, they are usually aimed a few degrees above the horizon to avoid ground clutter from nearby topographic features. This creates a gap between the radar fence and the ground, through which low-flying air threats can sneak in undetected. The Iranians apparently used this technique in earlier operations deep inside Saudi Arabia. In May 2019 two Saudi oil pumping stations in Afif and Dawadimi (770 and 820 km. respectively from the Yemeni border) were struck by UAVs, causing a temporary surge in global oil prices. On August 17 the Shayba oil field in eastern Saudi Arabia, almost 1200 km. from Houthiland, was struck, causing gas fires. Regardless from where the UAVs came from – they might have been launched locally by dissidents or by Houthi raiders – the fact is that they succeeded to slip through whatever defenses may have been protecting those installations. In many senses, the May and August raids were the precursors of the more devastating September 14 attack.

The Saudi armed forces have never disclosed the composition and location of their air and missile defense defending Khurais and Abqaiq, if any. Speculations about this issue abound in the media and on social networks. The speculations are futile. Defense systems require detection and tracking of their targets. Without detection there is no engagement and no interception. It stands to reason, then, that the inactivity of the Saudi air defenses was an inevitable result of the lack of early warning and detection. This had nothing to do with any real or imaginary flaws in the US- and European-supplied Saudi air and missile defense systems but with the fact that they were not designed to deal with ground-hugging threats. Simply put, the Iranians outfoxed the defense systems.

To summarize, the September 14 attack on the Saudi oil facilities was a brilliant feat of arms. It was precise, carefully-calibrated, devastating yet bloodless – a model of a surgical operation that reaped for Iran a rich political and military harvest at the minimal cost of a few cheap unmanned vehicles, yet with a low risk of retribution. The planning and execution of the operation was flawless. The Iranians managed to mask their own role, to divert responsibility to their Houthi allies, to sneak two flights of unmanned air vehicles into two of Saudi Arabia’s most important oil facilities, and to execute unprecedented precision strikes on their installations without even breaking a window in a nearby town. And all this with utter surprise, with no intelligence leaks and without being detected either upon launch or on the way to the targets. The US armed forces could not do any better.

Strategic and Political Aspects

While there is no information on who directed this feat of arms, there is no doubt that it was authorized by the highest level of government in Iran. Simply put, its strategic purpose was to knock Saudi Arabia out of the war. It stands to reason that this prospect became tempting after Iran’s success in knocking the UAE out of the war. In June 2019 the UAE announced that it was withdrawing most of its troops from Yemen and shifting from a “military first” to “diplomacy first” policy in that country. Speculations about UAE motives abounded. Yet the impact of the purported attacks on Dubai and Abu Dhabi international airports by long-range Houthi UAVs during the summer of 2018 cannot be dismissed. Whether these attacks actually took place is controversial. In May 2019 the Houthis released a video purporting to show security camera footage of an attack by a fairly large, straight-wing and most probably propeller-driven UAV on a truck park inside Abu Dhabi’s international airport, causing an explosion. The Emirati authorities conceded that an “incident involving supply trucks” had occurred in that airport but did not specify its nature or cause. The video could be fabricated. Abu Dhabi’s airport is almost 1400 km. away from Houthiland, and thus the prospects of a simple propeller UAV traversing this distance with no hitch are far from sure, and the video itself has some suspicious features. Yet, if the attack did occur, it might have damped the ardor of UAE to involve itself any further in the Yemen war. The UAE’s warning after the Sept 14 attack about the consequence of any attack on their major cities illustrates its concern.

Iran took big political and military risks by launching an attack of such magnitude on September 14. Had its key role in this attack been exposed right away, it night have faced both military retaliation from the US and diplomatic censure from the international community. That Iran was ready to take this risk indicates Iranian confidence in its ability to hide its role as well as confidence in US passivity. The Iranians clearly sense US reluctance to use force in the region. After all, the US failed to retaliate significantly after Iran shot down a $220 million American UAV several months ago. This, coupled with the UAE withdrawal, may have emboldened Iran to raise the stakes in its struggle for regional hegemony. It now threatens to raise the stakes even further, by threatening through the Houthis to launch further and even more devastating attacks on Saudi Arabia’s oil facilities.

Whether this will knock Saudi Arabia out of the war, leaving Iran the master of Yemen and the key holder of the Bab el-Mandeb straights remain to be seen. Nevertheless, this impressive feat of arms has raised Iran’s prestige in the region, and no less important within Iran itself, and this at a time when US sanctions are imposing hardships on the Iranian public. Judging by the hardly concealed glee in the tightly controlled Iranian press, the regime is exploiting its success to the hilt to ensure public resilience in face of the economic pressures.

Could this Happen to Israel?

To evaluate this question, we need to evaluate the September 14 attack in context. It was undoubtedly a landmark event that will be marked as one of the most audacious military surprises ever; a landmark event yet by no means a revolution in military affairs. UAVs of various kinds have been prominent in military operations since the 1980s. While the role of UAVs has been growing, UAVs have suffered their share of failures. Whether termed drones, UAVs or cruise missiles, these vehicles are basically the same; they are pilotless fixed-wing or rotary-wing aircraft, some rotor or propeller-driven and some jet-propelled. They come in many shapes, sizes and specifications. Some are small quadcopters powered by batteries (usually called drones); some are small fixed-wing aircraft powered by piston engines (usually called UAVs); and some are jet-propelled (ominously dubbed cruise missiles). To simplify, they can be bundled under the appellation Unmanned Air Vehicles – UAVs. Each type has its advantages and vulnerabilities. Some are as big as small airliners. Most are small enough to make it difficult (but not impossible) to shoot down. They are much cheaper than manned aircraft, hence their appeal to budget-starved armed forces and to impoverished guerilla organizations. The absence of human crews makes them admirably suitable for dangerous operations, since no loss of operator life is risked.  Yet, useful as they are, UAVs are not invulnerable.

UAVs have been successful engaged and destroyed almost from their first appearance on the battlefield. The first truly operational UAVs – the Nazi V1 “Doodlebugs” of WWII – were shot down in droves over England, suffering at times a 90% loss rate. In the 1991 Gulf war, Saddam’s air defense managed to shoot down several US Tomahawk cruise missiles by anti-aircraft guns, whenever they followed a predictable path. Israel destroyed over the years several hostile UAV using air-to-air missiles, ground-to-air missiles, and the rotary guns of Apache helicopters. US “Predator” UAVs have been downed by ground fire in Yemen and elsewhere. Saudi Arabia shot down several Houthi UAVs. The Russians in northern Syria are routinely shooting down UAVs launched by Syrian insurgents.

What was the secret of the Iranian’s success in the Sept 14 attack? While detailed information is still lacking, we can hazard some speculation about its ingredients. First is the successful maintenance of absolute secrecy which assured a complete surprise. The second factor is a good appreciation of the performance and vulnerabilities of Saudi Arabia air and missile defense systems. Third, a comprehensive intelligence picture of their deployment at the time of the attack. Fourth, a meticulous planning of flight paths to avoid terrain obstacles and to circumvent Saudi radars or fly below their horizons. Fifth, the last word in automatic optical homing to ensure surgical precision.

Of these five factors, the most decisive factor is the undetected access to the targets. The surgical precision was useful but not crucial. Even with coarser GPS guidance, and armed with explosive warheads, the incoming UAVs could devastate the Khurais and Abqaiq facilities, albeit less elegantly and probably with some loss of Saudi lives. Simply put, good secret-keeping and good intelligence allowed the Iranians to exploit the gaps in Saudi Arabia air and missile defense.

Could this happen to Israel? As noted, UAVs are not hard to shoot down, provided they are detected in time. Simple, relatively low-tech radar guided anti-aircraft guns can destroy low flying UAVs once they are detected. A good example of a simple yet effective close air defense system that can shoot down low flying UAVs is the Russian “Panzir” (SA-22), comprised of a radar, two 30 mm. cannons and 12 short-range ground-to-air heat-seeking missiles mounted on a truck chassis. Comparable systems can be improvised in the West in short order. More readily but more expensively, the Patriot system can shoot down UAVs, as was demonstrated by Israel during the 2014 Gaza war. The key question then is not how to shoot down UAVs but how to detect them in time. The Iranians sneaked through the inherent, built-in gaps in Saudi detection systems. Do such gaps exist in Israel, and if so, can they be closed?

When asked by CBS’s “Sixty Minutes” program why his county’s air defense systems failed to detect the incoming UAVs, Crown Prince Mohammed Bin Salman replied that “Saudi Arabia is almost the size of a continent. It is bigger than all of Western Europe. We have 360 degrees of threats. It’s challenging to cover all of this fully.” In other words, Saudi Arabia does not have a comprehensive, country-wide detection system, due to its huge size. There are probably only local “bubbles” of radar coverage, in between which low-flying raiders can penetrate. In contrast, Israel is one of the smallest countries in the world. Israel Air Force controllers routinely shush away civilian ultralight aircraft and paragliders that stray into no-fly zones – which are basically comparable to low-flying UAVs. It can therefore be deduced that Israel’s airspace is fully transparent to air force controllers, at least from a certain altitude and above. Whether there exists a gap between the detectability horizon of Israel’s airspace control radars and the ground, of the kind that allowed the Houthi and Iranian UAVs to sneak below radar coverage, is unknown. Still, even if such gap exists it can be easily closed by existing means such as inexpensive Doppler radars of the kind used in the US Marine Corps MRZR anti-drone system (These radars, incidentally, are of Israeli origin).

The sophistication of the September 14 attack in Saudi Arabia stands in stark contrast to the desultory efforts of Iran’s Quds force to strike Israel in recent times. Quds forces fired 32 rockets on May 10, 2018 targeting the Golan Heights. Most failed to reach Israel and fell harmlessly in Syria while four were shot down by Israel’s Iron Dome system. In January 2019 Quds forces near Damascus fired one rocket at Israel’s Mount Hermon. The rocket was destroyed by Iron Dome. On August 25, 2019 Israel frustrated a Quds force drone attack on its territory by destroying the base near Damascus from which the attack was to originate. These feeble, low-scale operations were aimed to retaliate against effective (and painful) Israeli strikes on Quds assets in Syria. The contrast to the level of effort and ingenuity invested by Iran in the September 14 attack on Saudi Arabia cannot be sharper. This disparity begs an explanation.

Perhaps the answer lies in Iran’s strategic priorities. It stands to reason that Yemen and the preservation of the Houthi regime takes precedence in Iran’s calculus; while confronting Israel is relegated, for the time being, to the back burner. There are important reasons for Iran to make this choice. The painful sanctions by the US probably contribute to its urgent need to break the logjam and bring Saudi Arabia to the negotiating table. When this is achieved, there is little doubt that Iran will turn westwards and ratchet-up its confrontation with Israel. No one can know when this might happen, but if and when it does, a September 14-style attack on Israel’s key infrastructures cannot be excluded. This is a serious threat. Israel’s successes thus far in the so-called “war between the wars” against Iran should not be taken for granted. Complacence is the mother of misfortune. The key to avoiding a Saudi-style debacle in Israel is prior intelligence and seamless early warning systems. Israel’s political and military leadership must draw the appropriate conclusions from Saudi Arabia’s “Black September.”


photo: Bigstock

One thought on “Saudi Arabia’s Black September

  • Islamic jihadist throughout the northern European universities have been honing these skills using the largest of the RC jet turbines (like the Swiwin series) since the 1990s. One cell that had started to practice at Grimbergen in the late 1990s dispersed after they realized they had piqued the interest of authorities. Given their access to technology, even at MIT in Cambridge through the Lebanese Christians, one should expect a rapid increase in similar attacks.

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