It has been a bloody weekend in the Gulf. The relentless war in Yemen has led to an economic blight in fractious Saudi Arabia and its economy that is fuelled by petro-dollars. Global supplies of oil will almost certainly suffer a “major jolt” following Saturday’s attack by drones on the world’s biggest oil processing plant in Saudi Arabia. The surgical strike on the primary asset of the desert kingdom was mounted by Houthi rebels, the primary target of the palace in Riyadh in course of a war that is seemingly without end.

The Houthis have promptly claimed responsibility without keeping the world guessing on so furious an offensive. Major fires engulfed the Abqaiq processing facility and the Khurais oil field after the attack. The rebels have admitted that they launched 10 drones with “intelligence cooperation from people inside Saudi Arabia”. The outlook is grim if the threat advanced by the rebels is any indication. Their operations “will expand and would be more painful as long as the Saudi regime continues its aggression and blockade” on Yemen. Ergo, the Saudi war against Yemen has acquired a new dimension.

Saudi Arabia’s oil fields and pipeline have been the target of rebel attacks over the past year, and often with the use of single drones. With the use of multiple drones, Saturday’s blitz was the biggest and most successful to date. Almost inevitably, the offensive has stoked tensions in the Gulf. Houthi rebels are assisted by Iran, which has developed sophisticated drones. The US Secretary of State, Mike Pompeo, has made confusion worse confounded, saying there was no evidence the strike came from Yemen; he has on the contrary accused Iran of launching an “unprecedented attack on the world’s energy supply”.

He is right in the perspective of the scale and impact, but the point of origin remains a matter of conjecture. Abqaiq, run by the state-owned firm Aramco, is said to be the world’s most important processing centre, where crude from several of the country’s largest oilfields is sent before being shipped for export. To use the language of the metaphor, Abqaiq is the heart of the system which has just been attacked. While the extent of the severity is yet to be calibrated, the attack has reduced production by five million barrels a day ~ nearly half the kingdom’s output and 5 per cent of global production.

This reduction will continue for at least 48 hours. The risk of tit-for-tat regional escalation is dangerously real. The overall tensions in the Gulf could well intensify after the US-Iran fallout over the former’s abrogation of the 2015 nuclear agreement. The drone attacks have raised the vulnerability of Saudi Arabia in the kingdom’s war against the Houthis. Hence the fear that Iranian-backed groups might use similar techniques elsewhere in the Middle East. The proxy war in the region has assumed awesome proportions.