Brent crude settled above $90 on July 20, 2026, up 1% on the day, as the United States launched its 10th consecutive night of strikes against Iran and a tanker was attacked in the Strait of Hormuz early on July 21 (Reuters; AP News; CNBC).

The US military said the strikes aimed to force the reopening of the Strait of Hormuz, a narrow shipping lane between Iran and Oman through which roughly one-fifth of the world's oil supply flowed before the conflict began. Iran has attempted to close the Strait since hostilities started (The Guardian; Al Jazeera). Iran responded by attacking US military bases across the Middle East, according to Al Jazeera's live blog dated July 21.

The conflict began on February 28, 2026, when US and Israeli forces launched joint strikes on Iran (Britannica). The IMF's PortWatch platform has tracked reduced traffic through the Strait since that date, classifying the disruption as "Trade disruptions in the Strait of Hormuz due to attacks on commercial ships" (IMF PortWatch).

Iran's Revolutionary Guards said two oil tankers were immobilised in the Strait, Reuters reported around July 21 (Reuters). The latest tanker attack came early Tuesday, July 21, per CNBC. Saudi crude exports fell for a third consecutive month as of July 21, Reuters separately reported (Reuters.

The Scale of the Disruption

The IMF put numbers on it. In a blog post dated July 15, 2026, the Fund said the war "effectively closed the Strait of Hormuz, cutting off some 20 million barrels a day of crude oil and refined products, a fifth of global consumption" (IMF Blog). That matches the pre-war baseline: about 20% of global oil supplies flowed through the Strait before the conflict began (Reuters). An earlier IMF blog, published March 30, called it "the largest disruption to the global oil market" (IMF Blog).

The price trajectory through July shows the pressure building. Reuters reported a 2% rise to a one-month high on July 14 as US-Iran attacks intensified, followed by further gains on July 17 amid renewed hostilities and threats of Red Sea closure (Reuters; Reuters). Brent's breach of $90 on July 20 marked the latest leg up.

On May 29, the heads of the IEA, IMF, World Bank Group, and WTO issued a joint statement warning that if shipping flows through the Strait did not return to normal, global oil inventories would continue to deplete rapidly ahead of peak summer demand (IMF). The IEA published its July Oil Market Report on July 10, covering supply, demand, stocks, prices, and refinery activity through the conflict period (IEA).

Military and Diplomatic Activity

US Secretary of State Marco Rubio said on July 19 that strikes were targeting Iranian assets used to attack global commercial shipping (US State Department). The State Department issued a Worldwide Caution on July 20 advising American citizens to exercise increased caution, and is hosting Foreign Ministerial Meetings from July 19 through July 23 (US State Department; US State Department).

Defense Secretary Pete Hegseth and Chairman of the Joint Chiefs of Staff Dan Caine publicly praised the success of a CENTCOM overnight strike on three Iranian nuclear sites, which used 30,000-pound GBU-57 "massive ordnance penetrator" bombs against the Fordow Fuel Enrichment Plant. The US military described that strike as "historically successful" (US Department of Defense; US Department of Defense).

What the Numbers Mean

The broader context here is one of diminishing buffers against a sustained supply shock. The IMF's July 15 assessment, titled "The Oil Market Absorbed the War Shock — But Buffers Are Running Low," frames the trajectory: the market initially absorbed the loss of 20 million barrels per day of crude and products through Hormuz, but inventory draws have accelerated through the summer. Think of it like a household burning through its savings to cover a lost paycheck — workable for a while, unsustainable indefinitely. The joint IEA-IMF-WBG-WTO warning from late May established the risk corridor; Brent above $90 in late July suggests the market is now pricing in the scenario those institutions flagged. Saudi Arabia's third consecutive monthly decline in crude exports is a concrete data point confirming that the supply-side adjustment is not just a futures-market phenomenon but a physical-flow constraint.

For anyone watching their portfolio, several tensions are worth tracking. The divergence between the IMF's March framing ("largest disruption to the global oil market") and its July language ("absorbed the war shock") captures a market that found an initial equilibrium through inventory draws and rerouting, but is now running on fumes. The State Department's concurrent diplomatic push (ministerial meetings through July 23) alongside a 10th night of strikes signals that no ceasefire is imminent; the US is running a military-maximum-pressure and diplomatic-exit-ramp strategy simultaneously. The CENTCOM strikes on nuclear sites, described as "historically successful," indicate the US has expanded its target set beyond commercial-shipping protection to Iran's nuclear infrastructure, which raises the escalatory ceiling considerably.

For inflation expectations, Brent persistently above $90 feeds directly into headline CPI (the consumer price index, the main gauge of inflation) through gasoline and diesel channels, complicating the Federal Reserve's decisions on interest rates. For credit markets, sustained elevated crude supports oil-producing sovereigns' fiscal positions while pressuring net importers. For equities, energy-sector earnings are the obvious beneficiary, but the demand-destruction risk at these price levels caps the upside. The key variable remains whether the Strait reopens or the 20% of global supply that flowed through it finds alternative routes at scale, which it has not.