The world's largest producer stepped in to fill the gap, but that cushion is shrinking.
At a narrow passage where one-fifth of the world's energy flows, the ancient calculus of conflict and commerce has once again collided. Iran's formal closure of the Strait of Hormuz, following fresh American military strikes on Wednesday, sent oil markets surging as traders priced in the fragility of global supply chains built on geopolitical trust. Brent crude rose to $95.40 and WTI to $92.63, numbers that carry within them the weight of a ceasefire unraveling and a world reconsidering how it powers itself.
- Iran declared the Strait of Hormuz closed to all vessels and threatened to fire on any ship attempting passage — a move that puts one-fifth of global oil and gas shipments directly in the crosshairs.
- The U.S. military contradicted Iran's closure claim, even as both sides traded accusations of missile and drone strikes, leaving markets unable to distinguish provocation from reality.
- The fragile ceasefire in place since early April has effectively collapsed, with fresh American strikes on Iranian targets Wednesday evening marking a dangerous new escalation.
- U.S. crude inventories fell 7.2 million barrels in a single week — nearly double analyst expectations — shrinking the buffer that has helped offset months of restricted strait access.
- Oil prices, already elevated by a prolonged partial blockade, now face the prospect of a sustained disruption with fewer strategic reserves available to absorb the shock.
Oil markets surged Thursday as Iran announced it had formally closed the Strait of Hormuz to all traffic, warning that any vessel attempting to transit would be fired upon. Brent crude closed at $95.40 a barrel, up 2.47 percent, while West Texas Intermediate rose 2.89 percent to $92.63. At one point during the session, futures had climbed more than $3 before pulling back.
The strait is no peripheral waterway — it carries roughly one-fifth of all global oil and gas shipments, and its closure, even threatened, reverberates immediately through energy markets. The U.S. military pushed back on Iran's declaration, stating that commercial vessels were still moving through, while both sides exchanged conflicting accounts of missile and drone strikes. What was not in dispute was the broader trajectory: the ceasefire that had held since early April was breaking down, punctuated by fresh American strikes on Iranian targets Wednesday evening.
Iran had been restricting strait access for months, keeping supply tight and prices elevated. But the formal closure announcement and the renewed military exchange raised the stakes considerably, with markets now pricing in the possibility of a prolonged disruption rather than a manageable standoff.
Adding pressure from the supply side, U.S. crude inventories fell by 7.2 million barrels in the week ending June 5 — far steeper than the 4 million-barrel decline analysts had forecast — bringing total reserves to 426.5 million barrels. Since the conflict began in late February, American crude stocks including strategic reserves had dropped by 79 million barrels in total. The United States had been drawing down its own supplies to compensate for the strait's effective closure, but that cushion is thinning. Should the conflict deepen and the waterway remain blocked, the market's ability to absorb the shock grows smaller with each passing week.
Oil markets lurched higher on Thursday as the prospect of a major global energy chokepoint shutting down sent traders scrambling to price in scarcity. Brent crude, the international benchmark, jumped $2.30 a barrel to close at $95.40, a gain of 2.47 percent. West Texas Intermediate, the U.S. standard, climbed $2.60 to $92.63, up 2.89 percent. Earlier in the session, futures had swung even higher, gaining more than $3 before settling back.
The trigger was Iran's military command announcing it had closed the Strait of Hormuz to all traffic—oil tankers, commercial vessels, everything. The declaration came with a stark warning: any ship attempting to pass through would be fired upon. This is not a minor waterway. The strait normally handles roughly one-fifth of all global oil and gas shipments. When it closes, the world feels it immediately in energy prices.
But there was a catch in the messaging. The U.S. military, posting on social media, contradicted Iran's claim, saying commercial vessels were still moving through the strait. The two sides were also trading accusations about military strikes. Iran's state media reported that American ships near the waterway had been targeted by missiles and drones. The U.S. military countered that no American warships had been hit. What was clear, though, was that the fragile ceasefire that had held since early April was coming apart. The U.S. launched fresh strikes against multiple Iranian targets at 5:15 p.m. Eastern time on Wednesday, marking the latest escalation in an exchange of attacks that threatened to spiral into full-scale war.
The blockade itself was not new. Iran had been restricting passage through the strait for months, keeping oil prices elevated as global supply tightened. But the American strikes and Iran's formal closure announcement ratcheted up the stakes considerably. Markets were pricing in the possibility that the disruption could last, that the two sides might not back down quickly.
On the supply side, U.S. crude inventories had fallen sharply. The Energy Information Administration reported that stocks dropped by 7.2 million barrels in the week ending June 5, bringing total reserves to 426.5 million barrels. That was steeper than analysts had expected—they had forecast a 4 million-barrel decline. Since the conflict began on February 28, American crude inventories, including strategic reserves, had fallen by 79 million barrels total. The United States, as the world's largest oil producer, had been drawing down its own supplies to help fill the gap left by the effective closure of the strait. That cushion was shrinking. If the strait remained closed and the conflict deepened, there would be fewer barrels to release into the market, and prices would likely stay elevated or climb further.
Notable Quotes
Iran's top joint military command announced the closure of the Strait of Hormuz, including oil tankers and commercial ships, saying any vessel that will attempt passage will be shot at.— Iran's military command
The U.S. military said commercial ships continue to transit in and out of the strait and that no U.S. warships have been struck.— U.S. military
The Hearth Conversation Another angle on the story
Why does Iran closing one waterway move oil prices so dramatically?
Because that waterway is the artery. A fifth of every barrel traded globally moves through the Strait of Hormuz. When it closes, there's no alternative route—you can't ship oil around it. The market has to immediately assume scarcity.
But the U.S. military said ships are still getting through. So is it actually closed?
That's the tension. Iran declared it closed and said it would shoot. The U.S. says traffic is continuing. What matters for prices is not what's true on the water right now, but what traders believe will be true next week, next month. The threat itself is enough.
The ceasefire broke in April. Why did it hold for two months?
Neither side wanted to absorb the cost of full war. But costs change. Something shifted—maybe domestic pressure, maybe a calculation that the other side was weakening. Once one side strikes, the other has to respond or lose face. It becomes a spiral.
The U.S. is drawing down its own oil reserves to stabilize prices. How long can that last?
Not long. They've already released 79 million barrels since February. That's a finite buffer. If the strait stays closed for months, they run out of cushion. Then prices have nowhere to go but up.
What happens to the global economy if oil stays above $95?
Inflation creeps back. Airlines raise fares. Shipping costs rise. Anything that moves gets more expensive. It's a slow tax on everything, and it hits poorest people hardest.