The United States is preparing a major escalation of economic pressure on Iran that Treasury Secretary Scott Bessent says will amount to the toughest sanctions ever imposed on Tehran. Washington wants not only to restrict Iran’s direct financial and commercial connections but also to make it increasingly difficult for foreign companies and countries to continue buying Iranian oil or providing access to the international financial system.
Bessent said the objective is to create an exceptionally broad level of economic isolation. The administration presents the strategy as a way of increasing pressure on Tehran without relying exclusively on military force. The complete details of the new sanctions package have not yet been announced, making it important to distinguish between Washington’s stated plans and restrictions that are already in force.
Iranian oil is likely to remain one of the central targets. Despite years of U.S. sanctions, Tehran has maintained significant exports through a complicated network of intermediaries, companies, ship-to-ship transfers and vessels commonly described as a shadow fleet. The U.S. Treasury has already sanctioned more than 100 vessels that Washington says have been involved in transporting Iranian crude and petroleum products.
But any attempt to dramatically reduce Iran’s oil revenues inevitably leads to China. According to data from Kpler, Chinese buyers account for more than 80% of Iran’s seaborne oil exports. That explains why Bessent publicly urged Beijing to cooperate with Washington’s campaign.
China has already signalled that it rejects this approach. Beijing argues that sanctions and pressure will not resolve the crisis and continues to advocate diplomacy. That creates a major challenge for Washington because significantly reducing Iranian exports may require secondary sanctions against foreign companies and financial institutions that continue doing business with Tehran.
Such measures could substantially increase pressure on Iran, but they would also carry the risk of a wider economic confrontation. If Chinese companies are forced to choose between commercial relations with Iran and access to the American financial system, the sanctions campaign could become another source of tension between Washington and Beijing.
Iran is already one of the world’s most heavily sanctioned economies. Restrictions cover banking, energy, shipping, companies and individual officials. Tehran has nevertheless spent years developing ways of operating around those measures through intermediaries, alternative payment mechanisms and networks of companies outside the country.
The emerging American strategy appears increasingly focused on those channels. In recent months, the Treasury Department has expanded actions against Iran’s shadow fleet, oil-trading networks and cryptocurrency structures that Washington says provide financial support to the Iranian authorities and the Islamic Revolutionary Guard Corps.
There is also a potential global cost. Removing significantly more Iranian oil from international markets could add upward pressure to energy prices, particularly while uncertainty surrounding the Strait of Hormuz remains high. China and other major Asian economies also have a strong interest in maintaining access to sufficient and competitively priced energy supplies.
This is the central uncertainty surrounding Washington’s strategy. The United States has enormous influence over the international financial system and can make trading with Iran considerably more difficult. But the broader secondary sanctions become, the greater the possibility that they will also damage relations with governments unwilling to follow Washington’s policy.
Bessent’s promised “toughest sanctions in history” will therefore test more than Iran’s ability to withstand economic pressure. They will also test how far Washington can persuade or compel other major economies to participate in Tehran’s isolation. The most important test may ultimately take place not in Iran itself, but in China – the country purchasing the overwhelming majority of Iran’s seaborne oil exports.
