None of the above came close to the effect of the drones launched by the Houthi rebels in Yemen – another country with a tradition of pipeline sabotage – against Aramco’s refineries in Abqaiq, the world’s biggest oil processing facility, on 14 September 2019. The unmanned vehicles swarmed into the precincts to puncture storage tanks, light fires, disable processing trains; in one fell stroke, half of the oil production in Saudi Arabia, accounting for 7 per cent of global supplies, had to be taken offline.
