US Treasury sanctions Iran's Hormuz network as Brent slides below $84

The US Treasury on Wednesday sanctioned what it called Iran's "Hormuz extortion network," targeting entities profiting from the Strait of Hormuz blockade as Brent crude futures held below $84 a barrel after a 5.1% decline.

"The sanctions target the financial infrastructure enabling Iran to weaponize the world's most important oil chokepoint," a Treasury Department official said, speaking on condition of anonymity because the announcement had not been made public.

The action freezes US-held assets of designated entities and prohibits American citizens from doing business with them. It comes as Iran has effectively shut the strait — which handled about 21% of global oil trade before the conflict — to most commercial shipping since the US and Israel launched strikes on Feb. 28. A partial reopening deal collapsed in early July after Iran fired on ships using an unauthorized channel.

The escalation threatens to reverse the recent oil price decline triggered by President Donald Trump's weekend decision to call off a two-week bombing campaign. Brent crude had fallen about 8% on Monday after the bombing halt, but the new sanctions risk reigniting supply fears through the waterway that carries about 20 million barrels of oil daily.

The Treasury's designation follows a period of diplomatic whiplash. Trump on Saturday abruptly ended 13 nights of US airstrikes on Iranian military targets, which had killed scores in Iran and destroyed bridges and tunnels across the south. Iran responded with attacks on US bases that killed four service members and strikes on civil infrastructure in Gulf states. US Central Command said Tuesday that Iran had launched multiple ballistic missiles in an attempted surprise attack on US forces, all of which were intercepted.

Oman had presented Iran with a plan backed by Gulf states to manage the strait, including collecting voluntary fees for transit — a system modeled on Asia's Strait of Malacca, where Indonesia, Malaysia and Singapore ask ships for voluntary contributions to fund navigation and environmental protection. But a US official reiterated Tuesday that Washington rejects any tolls or fees for ships transiting what it considers international waters. Iran's Deputy Foreign Minister Kazem Gharibabadi said Tehran had proposed to Oman that Iran manage one-way shipping through its side of the strait.

Oil Markets Face Renewed Uncertainty

The sanctions inject fresh uncertainty into oil markets that had begun pricing in a de-escalation. Brent crude futures settled at $83.72 a barrel on Monday, down from above $90 in early July before the partial reopening deal collapsed. The war has already cost US taxpayers an estimated $29 billion through last month, according to the Pentagon, with the Harvard Kennedy School projecting continuing costs of up to $2 billion per day. US gasoline prices have risen about 50% since the conflict began, Trump said at a Cabinet meeting.

Trump has insisted the strait "will be open to everybody" and warned he would resume strikes if negotiations fail. "If we don't make a deal, we'll take it out very easily," he said in a Fox News interview Tuesday, referring to Iran's fortified Pickaxe Mountain nuclear facility. Defense Secretary Pete Hegseth said Iran "cried uncle to talk" after the US implemented its naval blockade of the strait in mid-April.

Iran's joint military command has rejected a Trump proposal for damages to vessels to be paid from frozen Iranian assets, state media reported, saying any country or company accepting such payments would be denied passage through the strait. Iran has denied seeking any new negotiations with the United States, which it accuses of violating the agreement reached last month on a framework for talks.

Broader Regional Risks

The Strait of Hormuz tensions are compounded by a new front opened July 20 by Iran-aligned Houthis in Yemen, who declared a blockade of Saudi ports on the Red Sea and have fired ballistic missiles at Saudi oil tankers. Saudi Arabia said Tuesday its air defenses intercepted drones targeting oil facilities launched from Iraqi territory by Iran-backed militias. Jordan also reported downing a drone on Tuesday.

The last time the strait faced a sustained closure was during the Iran-Iraq war in the 1980s, when the Tanker War disrupted shipping and sent oil prices sharply higher. The current conflict has already pushed US gasoline prices about 50% higher since February, according to Trump's Cabinet meeting remarks. Secretary of State Marco Rubio described Iran as "the world's leading sponsor of terrorism," adding that while diplomacy is the first option, the US has "other options" if negotiations fail.

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