Global oil stocks face 6-month supply test as US-Iran war persists

Global oil stockpiles face their sternest test in decades as the US-Iran war enters a sixth month, with traders questioning whether inventories can offset what could become the largest supply disruption on record.

"China's oil imports have dropped roughly 50 percent since the conflict began, acting as a pressure valve for global markets," said Rory Green, head of emerging markets research at TS Lombard. "If oil imports had remained constant through the conflict, we could easily see oil at close to $200 a barrel."

Brent crude spiked to nearly $120 a barrel in the early weeks of the war before retreating to the high-$80s, while WTI has slipped below $82.50 as US inventories rose more than expected. The S&P 500 sits at record highs, and the Strait of Hormuz — which handles about 20 percent of global oil traffic — remains effectively blockaded by Iranian attacks on vessels.

The critical question is whether stockpiles can bridge a prolonged closure. TS Lombard estimates China holds roughly two months of reserves before domestic stress sets in, and if Beijing is forced back into the market aggressively to refill, prices could spike sharply. With peace talks between Iran and Oman stalling and WTI hovering near $81.50, the window for a diplomatic resolution is narrowing.

China's Two-Month Buffer

The last time the Strait of Hormuz faced a comparable threat was during the Iran-Iraq War in the 1980s, when the "Tanker War" disrupted shipping for years but never fully closed the waterway. Today's situation is different: Iran has effectively blockaded the strait with attacks on commercial vessels, and the conflict shows no signs of abating.

China's strategic petroleum reserve and commercial inventories provide roughly two months of cover, according to TS Lombard's Green. Erica Downs, senior research scholar at the Center on Global Energy Policy at Columbia University, noted that Beijing has spent over a decade building energy buffers, including massive petrochemical capacity, low inflation, and a large electrification build-out. These four buffers combined make China "very resilient to this energy shock," Green said.

The risk is that China's response function flips. If Beijing's authorities conclude the disruption will exceed their buffer window, the country could return to the market aggressively to refill stockpiles, pushing prices higher at the worst possible moment. Green noted that China's reduced imports throughout the crisis have acted like a pressure valve, but that dynamic could reverse quickly if reserves run low.

Market Transmission and the Inflation Channel

Angelo Kourkafas, senior global investment strategist at Edward Jones, said the primary transmission channel from the Middle East to financial markets runs through energy prices and inflation expectations. A second-quarter increase in inflation was largely driven by energy prices, he noted, though that pressure should gradually ease if the recent oil shock continues to fade. Housing-related inflation pressures continue to cool, and wage growth is becoming less inflationary when adjusted for productivity gains, he added.

The world is well supplied, even oversupplied, with oil absent this conflict, said Steve Wyett, chief investment strategist at BOK Financial. "This is a distribution issue, not a supply issue, and as such, the impacts to inflation and economic growth are being viewed as temporary."

But the distribution problem is the crux. Non-Gulf producers have increased output, nations have released emergency inventories, and alternative pipeline shipments have been deployed. Yet if the strait remains closed for another six months, those buffers will be tested. Defense-related companies may benefit from inventory replenishment spending as global supplies of military hardware dwindle, according to Mark Barmak Besharaty, founder of the Center for Iranian Prosperity, Holdings, Economics and Stability.

For equity investors, the historical pattern is instructive. Past geopolitical flare-ups have produced short-term volatility but limited lasting market damage. The S&P 500 has climbed out of its initial war dip to record highs, and Edward Jones views any volatility as an opportunity to rebalance portfolios rather than a reason to abandon long-term plans.

The next six months will determine whether the current stockpile cushion holds. If it does, oil prices should continue to moderate and inflation pressures ease. If it doesn't, the market faces a supply shock that could push crude well above $120 and force central banks to reconsider their easing paths.

This article is for informational purposes only and does not constitute investment advice.