The Middle East crisis isn't just about stranded tankers — oil output could be forced offline next

• US-Israel strikes on Iran threaten the Strait of Hormuz and global oil flows.
• A prolonged closure could fill storage tanks and force Gulf producers to stop pumping oil.
• Surging crude may lift US shale while stoking inflation and economic pressure at home.

Oil traders are bracing for disruptions to the Strait of Hormuz after the US and Israel struck Iranian targets over the weekend, putting at risk the waterway that carries about one-fifth of the world's oil.

A longer disruption would shift the risk onshore, because storage tanks across the Gulf can only be filled for only so long.

If the conflict drags on and export routes remain blocked, producers could be forced to halt production as storage fills up, Daan Struyven, the head of oil research at Goldman Sachs, said on Goldman Sachs' "Exchanges" podcast published Monday. This could send prices sharply higher.

"If the Strait of Hormuz is closed for a very long time, you cannot draw inventories forever, and the market may have to rebalance by incentivizing prices to such high levels that you generate demand destruction," Struyven added.

Oil prices are already sharply higher this year on the back of heightened geopolitical risks.

International benchmark Brent and US West Texas Intermediate crude oil futures are 3% and 2.4% higher at around $80 and $73 per barrel, respectively, in early trade on Tuesday. Both grades are up about 30% this year.

The Middle East accounts for about one-third of the world's seaborne crude.

"Gulf producers do have storage capacity, pipelines, and tanker alternatives, but these are not unlimited," wrote Chris Weston, the head of research at Pepperstone, in a Tuesday note.

"With the Strait of Hormuz temporarily constrained, the longer the disruption persists, the greater the risk that additional facilities and infrastructure across the Gulf region may be forced offline," Weston added.

JPMorgan analysts have also warned that if the strait is effectively closed for more than 25 days, storage constraints could push major Middle East producers to suspend output altogether.

'A supply shock of historic proportions.'

Iran's Revolutionary Guards said on Monday that the Strait of Hormuz is closed and they will attack any ship trying to cross the waterway.

Major lines are rerouting or suspending services and adding war-risk fees, while some marine insurers have canceled war-risk cover for vessels operating in and around Iranian waters.

Apart from oil, Qatar's state-owned energy company has halted liquefied natural gas production after reported damage to facilities, underscoring how quickly disruptions can spill beyond crude into wider energy markets.

The macro consequences could be severe, wrote analysts at ING on Monday, as even a partial disruption to the Hormuz would produce "a supply shock of historic proportions."

However, because the US is a major oil producer, higher oil prices benefit shale producers and improve the domestic energy industry.

Still, inflation could tick up for American consumers, so "that balance is politically awkward to explain and economically insufficient to compensate for the broader damage," wrote ING analysts.