Over thirteen years ago, at 2.25 pm on Friday, 24 February 2006, a three-vehicle al-Qaida attack group approached the Hamra gate to the Abqaiq oil processing plant 300 km east of the Saudi capital Riyadh. Choosing a Friday afternoon meant a particularly quiet time, but the gate was still guarded. The first vehicle, a Toyota Land Cruiser, carried three paramilitaries who attacked the guards while the second vehicle forced its way to the barriers before exploding, allowing the third vehicle to move towards the plant itself. (For the full story, see Jane’s Intelligence Review, May 2006, pp. 6-11.)

On Saturday morning, Abqaiq was attacked again – this time from the air, by drones and cruise missiles. The difference between the two attacks may explain why Donald Trump has been so cautious in his response to the more recent one.

In 2006 the official Saudi line was that the third vehicle exploded no nearer than 300 metres from core parts of the plant, though local sources spoke of some damage within the plant itself. Whatever the truth of this, the penetration of even the outer security of such a key facility was a matter of considerable concern. After all, it was hardly a new strategy, fitting in with a long-standing commitment to economic targeting by groups as diverse as the LTTE in Sri Lanka in the mid-1990s and the Provisional IRA in the 1992-97 campaign in the London area.

The 2006 attack may have caused far less damage than the al-Qaida paramilitaries intended. Still, as I wrote in my openDemocracy column published less than a week afterwards: “Perhaps the key lesson here is that determined and dedicated insurgents have a capacity to damage the economy of a country that far outweighs their numbers, even in the absence of much outside help.”

A few months later the Pentagon decided to upgrade US naval protection for the Ras Tanura oil terminal downstream from Abqaiq, the two facilities together being core components of Saudi Arabia’s huge oil export industry. As a further openDemocracy analysis put it:

That “willingness” was unexpected given the extreme Saudi sensitivity to allowing the ‘crusader’ forces of the US to have any direct military role in protecting the Saudi ‘Land of the Two Holy Mosques’ in Mecca and Medina. It indicates the importance of Abqaiq and Ras Tanura and also explains the massive Saudi investment in military equipment in the past two decades.

Where was the West?

Despite that investment, Saudi Arabia’s the supposedly sophisticated western-supplied air defence system failed to stop Saturday’s attack, and this has raised many questions over Saudi capabilities. Perhaps less noticed has been the question of how US and British forces in the region responded.

Houthis in Yemen claimed responsibility for this week’s attack but the Saudis say it was launched from Iranian territory. Either way the waters are thoroughly muddied. Saudi Arabia has been experiencing drone missile attacks from Yemen for over a year yet seems scarcely to defend itself against them in spite of its defence investments. But if the attacks came directly from Iran, why did western states not detect them?

While the US has very few uniformed military personnel based in the kingdom itself (the Ras Tanura oil terminal protection is mainly offshore) there is a considerable western presence in two neighbouring states, Bahrain and Qatar. Bahrain has the headquarters of the US Navy’s Fifth Fleet less than 100 km east of Abqaiq, with the Royal Navy base of HMS Juffair part of the wider complex. Juffair may not be large but in addition to its regular minehunter facility it now has a frigate and, more recently, an air defence destroyer. Even more significant for the Pentagon is the huge al-Udaid US air base less than 200 km to the south-east as the F-35 flies.

Whether or not the Abqaiq attack was detected while it was under way, the issue here is that two trends in the conduct of war are merging. One is the ability of states to attack through proxies and surrogates while denying any responsibility. This is hardly new, but the other trend is: the rapid proliferation of armed drones. When the Oxford Research Group’s Remote Warfare Project started a little over six years ago, only two states produced and exported such drones – Israel and the United States. But the group argued that a tipping point had been reached and many other states would join in, with little or no possibility of a parallel arms control regime developing in parallel.

That is what has happened, with a speed that has surprised even those behind the ORG work. Whereas in 2006 a movement such as al-Qaida needed suicide bombers to hit somewhere like Abqaiq, low-tech high-impact armed drones are increasingly widespread. The whole sphere of irregular warfare is getting a substantial boost.

Twenty-seven years ago, a prescient US military analyst and former submarine captain, Roger Barnett, wrote of new technologies in the post-Cold War era increasing “the ability – and therefore the willingness – of the weak to take up arms against the strong”. Given the caution with which Trump has so far responded to Abqaiq perhaps this an all too relevant example of what he had in mind.