In an effort to dismantle the sophisticated financial systems used by Iran to bypass international trade restrictions and to pressure Tehran into a deal, the US Treasury Department has called on the banking sector to heighten scrutiny.The initiative enlists private lenders to assist in identifying clandestine networks that move capital through front companies and digital assets to conceal proceeds from sanctioned oil sales.In particular, US banks have been instructed to closely monitor oil labelled as ‘Malaysian blend’, as this designation in shipping documentation is allegedly often used to disguise its Iranian origin.Other indicators mentioned include ‘missing or clearly falsified shipping records’ and the use of ship-to-ship transfers in the open ocean, which are designed to obscure the original source of the cargo.This is the latest development in the US government’s coordinated campaign, nicknamed ‘Economic Fury’, which launched in April. The initiative is designed to apply ‘maximum economic pressure’ and financially isolate the Iranian regime by systematically cutting off its primary revenue streams.On Monday, US Treasury Secretary Scott Bessent reiterated the Trump administration’s commitment to this strategy and announced that twelve individuals and entities had been designated as facilitators of the Islamic Revolutionary Guard Corps’ (IRGC) sale and shipment of Iranian oil.International shipping hubs under scrutiny by US authoritiesThe role of international shipping hubs has also come under increased scrutiny.According to the Financial Crimes Enforcement Network (FinCEN), a bureau within the US Treasury Department, dozens of maritime companies based in Iraq, the UAE and Hong Kong have been identified as participants in the transport of sanctioned Iranian oil.In a report released on Monday, US authorities found that these firms conducted transactions worth roughly $4 billion (€3.4bn) linked to Iranian oil companies and processed at least $707 million (€602mn) of those funds through US accounts in 2024.In April, the US Treasury Department had already sent formal correspondence to financial institutions in China, Hong Kong, the UAE and Oman regarding the issue.These letters carried a stern warning that secondary US sanctions could be imposed on any entity found to be facilitating Iranian business activities. They also accused these jurisdictions of allowing illicit transactions to pass through their domestic banking systems with limited oversight.As the ceasefire and further negotiations become increasingly precarious, the threat of being cut off from the US dollar remains a potent tool for Washington in its efforts to isolate the Iranian economy and pressure the IRGC.