Saudi Drone Attacks: A Preliminary Military Evaluation

On September 14, 2019, the state-owned Aramco oil refineries at Abqaiq (Biqayq in Arabic) and Khurais in eastern Saudi Arabia were successfully attacked using drones and cruise missiles. The damage caused to the refineries brought down Saudi Arabia’s oil production by almost 50 per cent1 - with a possible significant dent on its economy. It was assessed that the damage would take weeks to restore. Though Saudi Arabia declared that it would use its strategic reserves to ensure that the global oil supplies are not disrupted, a ripple was nevertheless felt when the global supplies experienced a five per cent reduction - albeit temporarily.2 The traditional supply of high quality Arabian light from the refinery was also temporarily replaced by the supply of mixed crude from the reserves.3 Consequently, there was an increase in oil prices by almost 20 per cent.4 In short, the attacks were able to cause the effect probably aimed at.

Though Houthis from Yemen had claimed the responsibility, the Saudi and the American experts were of the view that the drones were probably launched from across the Iraqi border by Iran or its proxies.5 Robert McNally, a former US National Security Adviser, said that “This attack was about Iran demonstrating that it has the means and will to execute exquisitely precise attacks on the most vital oil infrastructure in the world by far, and they can come back next Tuesday or a week from Friday – they can do this again.”6 However, both Iran and Iraq have rejected the contention.7

From a military point of view, the attacks demonstrated the capability of elements of air power to cause strategic and disproportionate damage when used correctly even in small measure against carefully selected targets. The attacks also demonstrated an exceptional level of mission accomplishment that is possible with drones today and in the process highlighted the trajectory of future warfare. The attacks had important lessons to offer from the military perspective. At this stage, since many of the details of the attacks are not fully known, only a preliminary analysis is feasible. But even a preliminary analysis has a lot to offer.

The attacks reportedly involved about 25 Kamikaze (sacrificial) drones comprising of 18 unnamed small sized Delta Winged Drones and seven ‘Ya Ali’ Iranian cruise missiles (range 700 km).8 Of these, 17 are reported to have impacted their targets very precisely – which is itself a feat. The drones/missiles are assessed to have made ingress from the north where the distance to the refineries from the Iraq border varies from 500 to 1000 km. Even from Yemen (south), the depth is about 800 to 1000 km. This is a very large distance to fly without being detected. Saudi Arabia reportedly had improper radar siting and gaps in low level radar cover that enabled ingressions from the north.9

Other major installations in Saudi Arabia including Abha International Airport and oil pipelines have been attacked a few times in the recent past with similar weapons by Houthis from Yemen. These attacks, however isolated, were on a small scale and not as sensational. No one had imagined the possibility of such a massive attack with drones as occurred on September 14. Rand specialists had earlier termed such a possibility as myth.10 They appeared to have overlooked what an advancing technology has made possible.

The attacks were carried out in two waves, one at 3:31 am and another at 3:42 am.11 These were still the darkness hours. The targets, which included gas storage spheroids and stabilising towers in the oil refinery, were carefully chosen to cause out-of-proportion damage to the oil production with minimal effort. 18 drones and three missiles were launched at Abqaiq and four missiles successfully targeted Khurais.12 Had the full complement of 25 vectors struck their targets, the damage would likely have been more catastrophic.

The Saudi official statement indicates that three cruise missiles meant for Abqaiq apparently fell short, probably due to inadequate range (target being further away),13 indicating their routing from the west - lengthening the route. Initial analysis by experts indicates that the cruise missiles were routed from the west, thus lengthening the route they had to take.14 Some of the debris was also reportedly recovered from the north-west regions of the targets.15 This is in sync with the notion of missiles having been launched from across the northern borders.

The size of the drones and missiles used indicate that the quantity of explosives would have been small. They resemble other autonomous sacrificial drones (like Israeli Harpy and Harop) which have a large range and strike the targets at high velocity and explode on hitting to cause damage. The nature of damage to the refinery is also indicative of the same.

Such an intricate operation, involving routeing drones to such depths through air defence cover avoiding detection and accurate targeting of the most vulnerable installations in oil refineries needs considerable intelligence, thus generally pointing to military expertise that is available only with states. The drones are likely to have flown their entire navigation route to target at low levels – below the radar horizons to avoid radar detection – otherwise, these would not have likely escaped the sophisticated radar inventory that Saudi Arabia holds. In the target area, the guards at the facilities apparently did unsuccessfully fire machine guns on the drones.

It was also noteworthy that the drones struck all the 14 spheroids (diameter approximately 20 m) at precisely the same spot.16 The kind of puncture holes that have been observed on these targets could have been made with only perpendicular hits on their surface by the drones - with small quantity of explosives that they could have carried and considering the robust construction of these spheroids. Such perpendicular hits are only possible through accurately flown attack profiles for each target. These kind of precise hits through precisely flown attack profiles on all 14 targets in darkness and in waves are not possible through manual control of drones. All this indicates the use of modern sophisticated technology for autonomous navigation as well as attacking the targets. The final homing onto targets may have been through GPS coordinates coupled with imaging infra-red sensing which could give pinpoint hitting capability autonomously. The Israeli Harop/Harpy drones and many other weapons have similar autonomous targeting principles.

The involvement of insiders in controlling the drones deep inside the Saudi territory, as some quarters have speculated, can be ruled out because there was still darkness when the drones struck. Controlling multiple drones flying at high speeds onto their targets in waves with the level of precision that has been achieved and in darkness is practically humanly impossible. Refineries are generally well lit but such lighting would rather be presenting hindering contrasts for someone trying to control drones visually or through night vision devices.

The success of the attacks has jolted the world into this new reality that seems to have opened up a Pandora’s Box requiring a whole new look at the threat paradigm. Such attacks on high value targets deep inside enemy territory are becoming more and more feasible and economical. Drones are no more very difficult to design. In the coming times, drones are likely to get an increasing share in augmenting the decisive role of the air power. Drones should no more be treated as adjunct. They are likely to become key tools of political-military signalling and hybrid warfare means with lesser risk of escalation in future.

Views expressed are of the author and do not necessarily reflect the views of the IDSA or of the Government of India.

• 1. Yun Li, “Saudi oil production cut by 50% after drones attack crude facilities,” CNBC, September 14, 2019 (Accessed October 20, 2019)
• 2. Ibid.
• 3. Shebonti Ray Dadwal, “The Abqaiq Attack – Fallout on Oil Market,” IDSA Comment, October 07, 2019 (Accessed October 20, 2019)
• 4. Guy Davis, “Oil prices jump by 20% after weekend attacks on Saudi facility,” ABC News, September 16, 2019 (Accessed October 20, 2019)
• 5. Michael Safi and Julian Borger, “How did oil attack breach Saudi defences and what will happen next?,” The Guardian, September 19, 2019 (Accessed October 20, 2019)
• 6. Ibid.
• 7. “Iraq denies its territory was used to launch attack on Saudi oil facilities: statement,” Reuters, September 15, 2019 (Accessed October 23, 2019)
• 8. Nael Shyoukhi, Lisa Barrington and Aziz El Yaakoubi, “Saudi says Iranian sponsorship of attack undeniable, displays arms,” Reuters, September 18, 2019 (Accessed October 20, 2019)
• 9. Michael Safi and Julian Borger, no. 5. Also, see Jeremy Binnie, “Saudi air defences ill-prepared for low-level attacks,” IHS Markit, September 20, 2019 (Accessed October 21, 2019)
• 10. Lynn E. Davis, Michael J. McNerney and Daniel Byman, “Armed Drone Myth 1: They Will Transform How War Is Waged Globally,” The Rand Blog, February 17, 2015 (Accessed September 16, 2019)
• 11. Omar Bishara, “Saudi Arabia Oil Field Burn in Massive Missile Strike, 5% of Global Oil Supply Goes up in Flames,” Al Sahwat Times, September 15, 2019 (Accessed October 21, 2019)
• 12. Nael Shyoukhi, Lisa Barrington and Aziz El Yaakoubi, no. 8.
• 13. Ibid.
• 14. Natasha Turak, “Detailed satellite photos show extent of ‘surgical’ attack damage to Saudi Aramco oil facilities,” CNBC, September 17, 2019 (Accessed October 21, 2019)
• 15. “Photos show precision of attack on Saudi oil plant,” Daily Sabah, September 16, 2019 (Accessed October 21, 2019).
• 16. Natasha Turak, no. 14.