Houthi attacks on Saudi Arabia have demonstrated that its build-up of batteries of air defence must stretch to all corners of the country.
Saudi Arabia is the world’s second-largest Patriot operator, said Nawaf Obaid of King’s College London’s Department of War Studies.
“Saudi Arabia does not lack air defences,” he told The National. “It possesses one of the world’s most sophisticated integrated air and missile defence architectures, protecting a country larger than Western Europe.
“The fundamental challenge is that no existing system, including those protecting the United States, can guarantee the interception of repeated, simultaneous attacks involving ballistic missiles, cruise missiles and drones.”
The kingdom is buying seven batteries of Thaad (Terminal High Altitude Area Defence), the largest programme outside the US, he added. The extensive use of missile interceptors during the Iran war has meant there is a need for renewed stocks, experts have told The National.
Despite having the world’s second-largest air defence system, 13 people were killed when King Khalid International Airport was struck by what are thought to have been ballistic missiles, causing widespread damage and leaving 308 wounded.
Countries around the world will now be looking at how to defend airports, but experts suggest close-in defence will be nearly impossible, given the number and size of civilian and military sites that could be attacked.
“An attack like the one we saw on Saturday on Riyadh Airport would in normal circumstances have been met with lavish application of Thaad at high altitude and Patriot on incoming,” said Dr Lynette Nusbacher, a former military intelligence officer.
“But what is clear is that Thaad and Patriot are not available in quantity and we’re seeing leakage.”
Interceptor expenditure
Military analyst Francis Tusa said the scale of interceptor expenditure during the war had put significant pressure on American stocks, with consequences for allies globally.
During one attack on a US airbase in Jordan, it is estimated up to 80 Patriots were fired in one night, leading to a rapid dwindling of the stockpile, he said. “The generals have told Trump that ‘we haven’t got the rounds left’.”
There is also the issue of the rebel Houthis' improving arsenal that includes manoeuvring ballistic missiles. The Iranian-derived Palestine-2 has a range of about 2,000km and hypersonic capabilities, including manoeuvrability, making interception more difficult during its terminal phase.
The US has expended an estimated 1,500 Patriots and has about 800 left. Saudi Arabia had more than 1,800 Patriot interceptors and has used a large number defending itself from Iran and the Houthis.
Saudi arsenal
Other defences include the South Korean KM-SAM, a medium-range system also owned by the UAE that is designed to intercept aircraft and incoming missiles.
British frustration
Saudi Arabia requested further defensive support from Britain's ministry of defence in the weeks leading up to the current attacks but the requests failed to secure ministerial approval. Saudi Arabian counterparts were left frustrated at the UK inaction.
The UK has contributed, with its Sky Sabre system providing a medium-range defensive layer using Common Anti-Air Modular Missiles, surveillance radar and integrated command-and-control systems, Mr Obaid said.
British industry can offer other options, which can be used for “point defence”, to stop close-in threats.
“The UK has got the Starstreak high-velocity missile, with 8km to 9km range, and is unjammable,” said Mr Tusa, editor of Defence Eye. “It’s also probably £100,000 [$132,300] a shot.”
The £40,000 Martlet missile, which uses a high-explosive warhead rather than Starstreak’s three tungsten darts, is another comparatively inexpensive option, he said.
As a vast country with considerable infrastructure, Saudi Arabia’s commanders have to decide where best to position radars and interceptors without being able to protect everywhere.
The resources for a single site are significant. “For Patriot, you’d normally get one, maybe two radars, two command systems, and four to six missile launchers,” Mr Tusa said.
Airport defences
Dr Nusbacher also questioned why commercial airports in the Middle East should be expected to have dedicated close-in air defence when comparable facilities in the West do not.
“Heathrow doesn’t have close-in air defence, and why would you expect King Khalid Airport to have close-in air defence?” she said.
Until recently, there was little expectation that Gulf states would face sustained attacks, she added. But the changing picture is now forcing a “major reassessment” of how civilian infrastructure should be protected.
Robert Tollast, a military analyst at the Royal United Services Institute, said defending one site could also leave others exposed.
There is a risk of “putting so much resource into interceptors around that facility that you leave other critical areas uncovered”, he said. Destroying energy infrastructure outside the summer months “could also be disastrous”.
One response would be to improve intelligence and attack missile launchers before they fire, as Saudi Arabia depends heavily on US satellite intelligence.
Given the scale of the emergency, US manufacturers are attempting to increase interceptor production – an estimated 2,000 Thaad and Patriots have been fired this year – but replenishing stocks could take up to 30 months.
Dr Nusbacher said defence planners had not anticipated the “profligate use of high-value, exquisite air defence systems” during a war “lasting more than a few weeks”.