Saudi Arabia logged its largest quarterly decline since the pandemic, and the figures reveal much more than the scale on the surface. GDP in the kingdom shrank 4.8 percent in the current quarter, compared with the previous quarter, according to the General Authority for Statistics' Thursday flash estimates. It is the biggest turnaround for Riyadh since 2020 and it's not due to a virus. The reason is the five-month old U.S.-Iran war, which has transformed the Strait of Hormuz into a geopolitical choke point and a shipping bottleneck.

The numbers behind the slump are grim. Oil activity, which remains the basis of the Saudi state's spending power, plummeted 24.7 percent from a year ago after increasing by almost 3 percent in the first quarter. That sector alone cut almost five and a half per cent from the overall growth rate. The sector, which Crown Prince Mohammed bin Salman has been pushing hard to develop as part of Vision 2030, has been trailing by a mere 0.6 to 0.9 percent in non-oil activity, falling far short of the $100 billion in output the prince had hoped to see by this point. One government spends a bit more, and the one that does more, and the overall message is clear: Saudi's economy suffers from chronic colds when the Hormuz gets the sniffles.

This has not changed, but the level of exposure this year has been astounding. Iran has repeatedly attacked tankers passing through Hormuz, where about a fifth of the world's oil and liquefied natural gas flows, and Washington has retaliated with a series of strikes on Iranian military sites with renewed naval blockades of ports near the strait this week. The Houthis' alliance with Tehran also has extended their front with threats to the Bab el-Mandeb strait and the Red Sea routes that Saudi Arabia is using as a bypass, including missile launches on pipeline facilities that supply the export terminal in Yanbu. It will be a swift test of the kingdom's resilience for this reason: Both its primary and backup shipping corridors were struck in the same few months.

But then again, the spin around resilience isn't just about Saudi. But in a report that was published only a day before the GDP numbers, the International Monetary Fund (IMF) has rated the kingdom's performance favourably compared with its neighbours, pointing to its low government debt, ample financial reserves and the robustness of the Public Investment Fund (PIF) to protect it from a war it did not call and cannot end by itself. The Saudi economy still sees a growth rate of 1.7 percent for the year as a whole, with non-oil growth slowing slightly to between 2.6 and 2.7 percent, assuming higher crude prices this year will partially offset falling exports. The oil price has been bouncing up and down in the Middle East, surging as high as 93 dollars a barrel during the height of the strike and settling around the mid-80s as shipping data from analytics firm Kpler indicated that traffic through Hormuz was starting to rise slowly toward a third of pre-war levels. It's up for grabs whether that recovery will last or not, as the events of recent history have shown, and how quickly hostilities can undo weeks of peace.

This contraction is different from the previous one in 2020, because it is the source of pain. Next came the destruction of demand and a battle of the producers. It's time to take the Saudi supply and logistics issue seriously, and as an added complication, Saudi Arabia is a combatant's neighbour, mediator, and target. A defence ministry official from Riyadh has been pushing for a multinational naval coalition including over 40 countries to protect shipping lanes, an unusually aggressive diplomatic ploy for a kingdom which, traditionally, has preferred to rely on Washington for security assurances. People familiar with the meetings say Crown Prince Mohammed's defence minister met with President Trump and Vice President Vance this week to advocate for a "more stringent and timely" reaction to attacks on Saudi land.

The more important question is what does this imply for the larger Vision 2030 investment in the tourism, entertainment, tech and manufacturing project, a multi-trillion dollar wager to shield Saudi Arabia from this type of oil shock? Non-oil growth of less than one percent in one quarter as the government sought to gain double-digit momentum in giga-projects is a sobering indicator, though analysts do not expect to draw too many conclusions from a quarter marred by war. In London, Capital Economics economists have suggested that this print may mark the peak of the damage as a result of the sharpest period of the conflict, and that the kingdom is likely to post around flat growth at the end of this year. Others are not so optimistic as its advocates, because, as long as Hormuz and the Red Sea are still problematic rather than peaceful sea lanes, there will still be a rough road ahead.

Riyadh is in a familiar, yet uncomfortable position: it is wealthier than usual and can be protected in the short term by its sovereign wealth and reserves, but structurally remains dependent on a commodity whose flow relies on the goodwill or at least the restraint of forces far outside its control. The diversification narrative is alive and well but this quarter should give an indication of how much time it will take for oil to cease to be the engine that drives the Saudi economy's growth or contraction.