The United States has blocked 70 oil tankers, disrupting Iranian crude shipments worth an estimated $13 billion. The move targets the backbone of Tehran's export revenue and marks one of the largest single enforcement actions against Iran's oil trade in recent years.
How the blockade works
The tankers were prevented from reaching their destinations through a combination of sanctions designations, tracking measures, and diplomatic pressure on ports and insurers. Without a clear flag state or legal cover, many of the vessels now sit idle or have been forced to turn back. The US Treasury and State Department coordinated the action, which effectively freezes the cargoes in place.
The $13 billion figure
The blocked cargoes represent a significant chunk of Iran's annual oil export earnings. At current market prices, 70 very large crude carriers can hold roughly 140 million barrels — worth about $13 billion. For Iran, which relies on oil sales to fund its budget and support allied groups, the loss is substantial. The country has already seen export volumes drop sharply under US sanctions, and this latest step could cut them further.
What comes next
The US has not announced additional measures, but the action signals that Washington is tightening the noose on Iranian oil revenue. The tankers' owners and operators now face a choice: abandon the cargoes, attempt to reroute through channels that risk secondary sanctions, or negotiate with US authorities. Iran has yet to issue an official response, and it remains unclear how it will try to circumvent the blockade. The $13 billion in disrupted exports will be felt acutely in Tehran, where hard currency is already scarce.
