On 14 September 2019, drones were used to attack oil processing facilities at Abqaiq and Khurais in eastern Saudi Arabia. The facilities were operated by Saudi Aramco, the country's state-owned oil company. The Houthi movement in Yemen claimed responsibility, tying it to events surrounding the Saudi intervention in the Yemeni civil war. Saudi Arabian officials said that many more drones and cruise missiles were used for the attack and originated from the north and east, and that they were of Iranian manufacture. The United States and Saudi Arabia have stated that Iran was behind the attack while France, Germany, and the United Kingdom jointly stated Iran bears responsibility for it. Iran has denied any involvement. The situation exacerbated the 2019 Persian Gulf crisis.
The attack caused large fires at the processing facility, which were put out several hours later, according to Saudi Arabia's Ministry of Interior. Both facilities were shut down for repairs, cutting Saudi Arabia's oil production by about half – representing about five percent of global oil production – and causing some destabilization of global financial markets. The Ministry of Energy said that the country would tap into its oil reserves to maintain export levels until the facilities return to full capacity by the end of September.
Background
Saudi Arabia is the world's largest oil exporter, having produced about 12 million barrels of petroleum products per day in 2017. Its proven oil reserves are the second-largest of any country, after Venezuela, and represent about 16% of the world's total.
Saudi Aramco, a national oil company owned by the Saudi Arabian government, operates several oil drilling, transport, and production facilities across Saudi Arabia. It is the second-largest oil producer in the world, behind Russia's Rosneft.
Aramco says the Abqaiq facility is "the largest crude oil stabilization plant in the world"; it converts sour crude into sweet crude oil by removing sulfur impurities before it is transported to downstream refineries, processing more than 7 million barrels of oil per day, about 7% of global oil production. Bob McNally, a former member of the United States' National Economic Council and National Security Council, told Reuters that "a successful attack on Abqaiq would be akin to a massive heart attack for the oil market and global economy". The Abqaiq facility had been the site of a failed suicide bombing by Al-Qaeda in 2006. The Khurais oil field, also operated by Aramco, produces about 1.5 million barrels of crude a day, and is estimated to hold up to 20 billion barrels of oil.
The Abqaiq oil facility was protected by three Skyguard short-range air defense batteries. Neither the Skyguards nor the other Saudi air-defense weapons — MIM-104 Patriot and Shahine (Crotale) — are known to have brought down any of the attacking weapons. A CNBC report offered multiple potential explanations, including that Patriot is optimized for interceping "high-altitude ballistic missiles" and that the Saudi troops operating the defenses "have 'low readiness, low competence, and are largely inattentive.'" The Guardian newspaper wrote that the defenses "would likely have been pointed across the Gulf towards Iran and south towards Yemen, but at least some of the missiles and drones are believed to have struck from the west." On 26 September 2019 Defense News published remarks by the Israeli air and missile defense expert Uzi Rubin, in which he characterized the Abqaiq–Khurais attack as "a kind of 'Pearl Harbor,'" saying "it will spark a lot of solutions" to the tactic of using unmanned aerial vehicle swarms plus low-altitude, high-speed cruise missiles.
Attacks
At around 4:00 a.m. Saudi Arabia Standard Time (UTC+3), Saudi Aramco reported fires at its Abqaiq facility as well as its Khurais facility. These facilities are several hundred kilometres distant from each other. At the time, about 200 people were in the Khurais facility, according to Aramco officials. The fires were contained a few hours later, according to officials. Though no fatalities were reported in the incidents, it was left unclear whether anyone was injured in the attacks.
Saudi Arabia's interior ministry said a few hours later that the fires were "a result of ... drones". Several unmanned aerial vehicles (UAVs or drones) were reported to be involved. A spokesman for the Saudi-led coalition fighting Iranian-backed rebels in Yemen, stated that 25 drones and missiles were used. Guards at the facilities reportedly tried to bring down the drones with machine gun fire, as captured on surveillance recordings of the facilities. According to Aramco, the drone strikes were in at least two waves; as they were evacuating the Khurais facility and dealing with fires from the first attack, another round of drones struck the facility.
Analysis of satellite images of the Abqaiq facility before and after the attacks appear to show 19 individual strikes: 14 that punctured storage tanks, 3 that disabled oil processing trains, and 2 more that damaged no equipment. A US interim report found that the attacks originated from the north.
According to the NCRI, the attack came from the Omidiyeh military base in Ahvaz.
UAV defense
Saudi Arabia's missile defense system failed to stop the swarm of drones and cruise missiles that struck the oil infrastructure. It is reported that Saudi Arabia has at least one MIM-104 Patriot missile defense system in place at Abqaiq. The missile defense system used was designed to mitigate threats from "high flying targets". Unmanned aerial vehicles and cruise missiles fly at an altitude too low to be detected by conventional radar systems. A swarm of drones and cruise missiles coming from multiple directions can confuse and jam radar, as well as overwhelm air defenses. In addition to the Patriot system, at least four shorter-range defense systems were present, yet also failed to detect and mitigate the drone attack. Drones are too difficult to detect by traditional methods; drones are also cheap and extremely accessible. The drones used may have cost around $15,000 or less to build. According to Justin Bronk, research fellow at the Royal United Services Institute in London, "the cost curve is very favorable to the attacker, meaning Saudi Arabia would have to spend far more than its enemies to protect against additional strike capabilities. As such, there is almost no way the Kingdom can completely defend against such attacks."
Attackers
In an initial report on 14 September 2019, the Saudi Arabian interior ministry did not identify the source of the attack, but stated they had begun an investigation. A statement from the French Foreign Minister in the early stages after the attack came on 17 September 2019, when he said, "The Houthis...announced that they launched this attack. That lacks credibility," but he went on to reference an ongoing international investigation, saying "let's wait for its results."
Hours after the attack, the Houthis said in a statement that they sent ten newly developed drones equipped with propeller and turbojet engines to disable the oil production facilities, and vowed to send more against a wider range of Saudi targets. They said they attacked in retaliation for the Saudi Arabian-led intervention in Yemen, which began in 2015, has killed thousands of Yemeni civilians, and has created a famine and a humanitarian crisis described in 2019 as the worst in the world. A military spokesman for the Houthis said, "These attacks are our right, and we promise the Saudi regime that the next operation will be wider and more painful if blockade and aggression continues".
In the weeks before the Abqaiq–Khurais attack, similar drone strikes on Saudi Arabian oil production infrastructure had caused no significant damage. The frequency of Houthi attacks increased throughout 2019, with the targets including a Saudi airport.
The military spokesman said that the Sept. 14 attacks came after a "careful intelligence operation, prior monitoring and cooperation from honorable and freedom-seeking people within the kingdom". The use of operatives inside Saudi Arabia would appear to address some of the technical objections about how the Houthis could have struck targets at such a distance.
On 16 September, the Houthis warned of more attacks on Saudi Arabia's oil infrastructure, and warned foreigners to leave Saudi oil plants.
They had displayed some of their long-range UAVs to the media in July 2019. The range of the drones reportedly can reach distant areas in Saudi Arabia and the United Arab Emirates. The Houthis had often used Samad 1 to attack Saudi Arabia. Later, the Houthis used the Quds 1, which is a small ground launched cruise missile that was possibly used in the 12 June 2019 Abha International Airport attack, which occurred in southwestern Saudi Arabia. A Houthi leader, Mohammed al-Bukhaiti, said that they have "exploited vulnerabilities in the Saudi defense system" and they "built their drones in order to avoid these systems, therefore, the Saudi and the Emirati airspace became open to us after their defense system failed to even spot our drones".
Houthi rebels have previously advocated targeting Aramco. The Rapidan Energy Group and the Center for Strategic and International Studies had both warned that the site of the attack was a vulnerable target.
At a press conference on 18 September, Houthi military spokesman Yahya Sarea said that they had launched a serious attack and Americans were using fabricated satellite images in an attempt to portray the resulting damage as having been minimal. He presented aerial photos of the Abqaiq and Khurais facilities, from before the attack, and said that they had been taken by Yemeni drones. He said that the Houthis had launched the attack from three locations. Third-generation Qasif drones were launched from one position, Samad-3 drones from a second position, and from a third position they had launched newly developed drones which use cluster heads, capable of dropping four accurate, independently targeted bombs. He said that they would soon display these newly developed drones. He stated that they were now capable of manufacturing drones rapidly.
Yahya Sarea threatened the United Arab Emirates which is part of the Saudi-led coalition, saying that they have a list of targets inside the UAE among them Dubai and Abu Dhabi. He said if the UAE "wants peace to its buildings which are made of glass and can't handle an attack by the Yemeni drones then leave Yemen alone". In response, UAE officials told The Telegraph newspaper that an attack by Houthis on tourism and global business hubs, would be an attack on the world.
Jean-Yves Le Drian, France's Minister of Foreign Affairs, stated on 19 September that preliminary findings from the investigation appear to rule out the Houthis' involvement and their claim "lacks credibility", but there would be no definitive conclusion until the international investigation is complete.
Officials for the United States had rejected the Houthis' claims, and instead said that Iran was responsible for the attacks. In the months prior, tensions between Iran and the United States created a crisis in the Persian Gulf, coupled with Iran's violations of the Joint Comprehensive Plan of Action related to their nuclear program in July 2019. On the day of the attacks, an unnamed senior US official said that Iran, not the Houthis, were behind the attack, which involved some dozen cruise missiles and more than 20 drones. The US said that it was working with Saudi Arabia to help investigate the attack and assure the facilities and energy supplies are secure and stable; US Secretary of State Mike Pompeo said that Iran was behind the attacks. US President Donald Trump initially stopped short of definitively blaming Iran for the attack, saying in an 18 September 2019 Newsweek article that "it was 'looking like' Iran was behind the attack."
Royal Saudi Air Force Colonel Turki al-Malki, a spokesperson for the Saudi-led coalition, issued a statement on 16 September saying that the drones appear to have been based on Iranian drones and that they were unlikely to have been launched from Yemen, counter to the claims of the Houthis. However, al-Malki said the coalition was still trying to determine the origin of the drones. At a press conference on 18 September, al-Malki showed debris of the drones, stating there were 18 drones and 7 missiles used in the attack (25 weapons in total), with the drones being delta wing-style craft of Iranian manufacture. Al-Malki showed surveillance footage that had, according to him, caught the drones traveling southward towards the facilities before the strike. He stated that this ruled out Yemen as a point of origin due to the range they would have had to have travelled. He concluded that this evidence "point[s] to Iran", and that the attack was "unquestionably sponsored by Iran". Iranian Defense Minister Brig. Gen. Amir Hatami stated in response to this new evidence, "These accusations are wholly, seriously and firmly rejected. It's easy to accuse someone without providing any proof."