The United States has taken steps to curb Iran’s use of an extensive network of aging tankers, often referred to as the country’s “shadow fleet,” which illicitly transports Iranian crude oil, petroleum, and petrochemical products to international markets. On October 8, the U.S. Treasury Department imposed sanctions on 17 vessels linked to this fleet, signaling ongoing efforts to block Tehran’s unconventional oil exports.

Despite these measures, reports emerged shortly after the sanctions were announced that the Biden administration is considering easing some restrictions on individual shadow-fleet vessels. This potential policy shift aims to address soaring freight rates, particularly in the strategic Strait of Hormuz, where insurance costs linked to war risks can reach between 7.5% and 10% of a ship’s hull value, and daily charter fees for supertankers have surged to as much as $1.3 million. Discussions include possibly lifting sanctions selectively to allow certain tankers to change ownership, potentially enabling their reintegration into legitimate maritime commerce under new, U.S.-aligned operators.

Industry analysts note that Iran’s shadow fleet has been significantly impacted by a parallel U.S. naval blockade and sanctions regime. According to the maritime intelligence firm Kpler, Iran’s export terminals failed to load any crude oil onto ships during September, a development that contrasts with other nations’ sanctioned tankers, such as those linked to Russia or Venezuela, which have largely continued trading. Kpler estimates there are approximately 160 supertankers under U.S. sanctions, most under 20 years old, though only about two dozen might realistically resume mainstream commercial shipping if sanctions are eased.

One of the main challenges lies in the continued transportation of Gulf crude through the Strait of Hormuz, a vital oil chokepoint. Given the high operational costs driven by war-risk insurance and charter rates, operators often resort to employing older vessels from the shadow fleet, as these represent the lowest cost option despite their age and risk profile. Research firm Energy Aspects suggests that sanction relief for select vessels could increase the pool of available ships for shuttle runs in the region, with established mainstream operators likely interested in acquiring operational vessels if doing so means restrictions can be lifted. Conversely, the oldest tankers may be retired and sold for scrap.

Sanctions enforcement often encounters the problem of owners shifting to alternative customers willing to absorb sanction risks. A comparable pattern emerged after sanctions were placed on China’s Yulong Petrochemical in October 2025, when suppliers including BP and Saudi Aramco ceased shipments, prompting the company to increase reliance on Russian crude significantly.

Former Treasury Department sanctions official Miad Maleki, now a senior fellow at the Foundation for Defense of Democracies, highlighted the potential for the U.S. to incentivize owners to divest these vessels. He cited precedents where ships and companies were removed from sanction lists following ownership changes, including two container ships recently delisted after acquisition by U.S.-aligned parties. Maleki argues that U.S. policymakers should expand this approach by actively facilitating the sale of shadow-fleet tankers to operators aligned with Washington, ensuring flag states and registries only reinstate insurance and finance access upon legitimate transfers. Older vessels could then be scrapped under similar terms.

Maleki contends that while Tehran constructed this black market to evade sanctions, current U.S. blockade efforts have rendered it largely ineffective. Rather than dismantling these sanctions, Washington could strategically open a controlled channel through which the fleet operates under new management, effectively stripping the Iranian regime of its fleet’s influence and value.