The US has confirmed deliveries of Patriot anti-missile systems to Saudi Arabia to counter increasingly frequent and accurate Yemeni rebel rocket and drone attacks on the kingdom's oil infrastructure.
This was revealed as Washington urged Riyadh to increase oil exports to alleviate rising fuel prices following Russia's invasion of Ukraine.
An unnamed senior US official said the transfer reflected President Joe Biden's pledge that "America will have the backs of our friends in the region" despite his administration's pivot east to counter China.
The US announcement followed last weekend's Yemeni rebel strikes on Saudi Arabia's vulnerable oil and gas facilities, reducing oil output at the Yanbu petrochemical plant and setting alight a tank at a distribution depot in the port city of Jeddah.
This co-ordinated attack is seen as the most effective mounted by rebel Houthis since the 2019 drone strikes that disrupted half of Saudi production by targeting two key oil processing installations in the Eastern Province.
The Saudi foreign ministry warned it would not “bear any responsibility” for a reduction in the world’s oil supplies caused by Houthi attacks, and called on the international community to “assume its responsibility to maintain oil supplies”.
In January the Houthis not only targeted Saudi Arabia but also mounted three drone and missile strikes on the United Arab Emirates. These attacks were in response to Saudi air strikes on the Houthi-held Yemeni capital Sana'a, and a joint Saudi-Emirati offensive to prevent the rebels from capturing oil-rich Marib province.
Success could have marked a major turning point in favour of the Houthis in the devastating stalemated war launched by the Saudis and Emiratis in March 2015. More than 377,000 Yemenis have died and four million been made homeless.
Oil exports
The Saudis and Emiratis have also rejected US pressure to increase oil exports even if Russia’s exports of five million barrels a day are cut or halted by fighting or sanctions imposed on Moscow for waging war on Ukraine.
US-Saudi relations have soured since July last year when the Biden administration released portions of a classified intelligence report alleging Saudi crown prince Mohammed bin Salman approved the 2018 murder of dissident Saudi journalist Jamal Khashoggi at the Saudi consulate in Istanbul.
Mr Biden's refusal to engage directly with the prince has deepened the rift and accelerated Riyadh's diversification of relationships by co-operating with Russia over oil exports, cultivating ties with China and co-ordinating independent policies with the Emirates.
This month Riyadh responded to Biden administration concerns over Saudi human rights abuses by staging the most mass executions in the kingdom’s history by putting to death on a single day 81 men sentenced for terrorism. Another seven were subsequently executed.
Reports that US secretary of state Antony Blinken would visit Riyadh soon have been denied.