Iran Faces New US Sanctions As Hormuz Oil Flows Collapse And China Comes Under Pressure

The United States will impose what Treasury Secretary Scott Bessent called the “toughest sanctions in history” on Iran, combining new economic measures with an existing U.S. blockade as Washington seeks to pressure Tehran without a major new military escalation. Bessent said Aug. 20 that details of the sanctions would be announced Aug. 24.

President Donald Trump had warned a day earlier that countries providing Iran with “any type of lifeline” would face economic consequences. Bessent said the administration was seeking cooperation from U.S. allies and other countries, placing Iran’s oil trade and financial links at the center of the next phase of the pressure campaign.

US Links Sanctions to Existing Iran Blockade

Bessent described the strategy as a “one-two punch,” combining the blockade with additional sanctions intended to restrict Iran’s access to revenue and international commerce. He said the administration expected maximum economic pressure to reduce the likelihood of another large-scale military operation.

The U.S. Central Command says American forces are enforcing a blockade of Iranian ports and have redirected 91 commercial ships as part of the operation. CENTCOM also said U.S. Marines had boarded commercial vessels suspected of attempting to violate the blockade, showing that the measure extends beyond financial restrictions to maritime enforcement.

The White House has previously described the blockade as an effort to restore navigation through the Strait of Hormuz, while China has called for the strait’s security and normal navigation to be restored and warned that military escalation threatens international trade.

Hormuz Disruption Keeps Oil Markets on Edge

The Strait of Hormuz carried roughly one-fifth of globally traded oil before the conflict, according to Reuters’ Aug. 21 assessment of the disruption. The reduction in shipping through the waterway has left millions of barrels of Middle Eastern oil stranded and pushed crude prices higher.

Reuters reported that only seven commodity ships navigated the strait on Aug. 21, half the number recorded the previous day. Brent crude reached $94.71 a barrel before retreating, while the disruption remained a central risk for energy markets.

The U.S. Energy Information Administration has separately estimated the effects of Hormuz-related supply disruptions on producers including Kuwait, the United Arab Emirates, Iraq, Iran and Qatar, illustrating how restrictions on the waterway can affect several major energy exporters simultaneously.

China Becomes the Critical Test for Washington’s Strategy

China is central to the sanctions strategy because Beijing remains a major economic partner of Tehran. Washington’s latest warnings therefore extend beyond Iranian entities to countries and companies that continue providing financial or commercial support to Iran. Bessent specifically urged China to cooperate with the U.S. pressure campaign.

China has rejected the premise that sanctions and pressure can resolve the conflict. In July, Chinese Foreign Minister Wang Yi said the priority was to resolve differences through dialogue and negotiations and to address issues surrounding the Strait of Hormuz through diplomatic efforts.

Beijing has also said that the strait is an important international trade and energy route and that maintaining regional security serves the interests of the international community. China’s Foreign Ministry said March 2 that relevant parties should stop military operations and prevent further escalation from damaging global economic growth.

Iran Faces Greater Economic Pressure

Iran’s ability to absorb additional sanctions is already under pressure from restrictions on oil exports, financial transactions and maritime commerce. Reuters reported Aug. 20 that the U.S. blockade had already reduced Iranian oil exports to China, adding a direct constraint to Tehran’s principal remaining external oil market.

Iranian political leaders have rejected the new U.S. pressure campaign. Reuters reported that Parliament Speaker Mohammad Baqer Qalibaf acknowledged the economic impact while arguing that Iran needed to address domestic financial difficulties rather than accept Washington’s demands.

The next major development is expected Aug. 24, when Bessent has said he will provide details of the sanctions. Until then, the combination of financial restrictions, maritime enforcement and pressure on third-country trade leaves the main uncertainty centered on how China and other major trading partners respond.