US turns stablecoin issuer Tether into a financial weapon against Iran, freezing nearly $500 million

An important story is making waves across the blockchain ecosystem. US authorities have used Tether's control over its dollar-linked stablecoin to freeze about $475 million connected to Iran in less than three months, extending Washington's sanctions reach beyond the traditional banking system. On July 14, the US government sanctioned four wallets on the Tron blockchain holding roughly $131 million in USDT. These addresses are linked to the Central Bank of Iran, also known as Bank Markazi.

Tether Freezes 4 Tron Wallets Holding Iran Central Bank's $131 Million (Source: Specter) Treasury Secretary Scott Bessent said the Office of Foreign Assets Control (OFAC) targeted the wallets as part of a broader effort to disrupt revenue networks that Washington accuses Iran of using to evade sanctions. He said US authorities would continue to trace and restrict the movement of those funds. The measures came as hostilities between Washington and Tehran intensified around the Strait of Hormuz.

Market Dynamics

US Central Command said it would resume restrictions on maritime traffic entering and leaving Iranian ports beginning July 14, after announcing fresh strikes against Iranian military targets in the preceding days. Meanwhile, the latest sanction follows Tether's April freeze of more than $344 million across two other Tron wallets. At the time, the company said it acted in coordination with OFAC and US law enforcement after authorities identified the addresses.

Together, the two actions have immobilized about $475 million that US officials have tied to Iran, making Tether an increasingly important instrument in Washington's campaign to limit Tehran's access to dollar-denominated assets outside the banking system. Tether can enforce those restrictions because it controls the contracts governing USDT. The company can block an address and prevent tokens held there from being moved, even though the wallet and its balance remain visible on the public blockchain.

Washington targets Iran's crypto infrastructure. The latest freeze extends a widening US campaign against the cryptocurrency infrastructure Iran uses to obtain and move dollar-denominated assets outside the traditional banking system. Under an enforcement initiative known as Operation Economic Fury, the Treasury Department has targeted crypto exchanges, intermediaries, and blockchain addresses that US officials say have helped the Iranian government evade sanctions and finance military operations.

Market Impact

In June, the Office of Foreign Assets Control sanctioned Nobitex, Bitpin, Ramzinex and Wallex, four exchanges that handled a substantial share of Iran's digital-asset activity. Treasury said Nobitex processed more than half of the country's crypto inflows in 2025 and helped the Central Bank of Iran acquire hundreds of millions of dollars in stablecoins. The exchange sanctions and wallet freezes show how Washington's approach has moved beyond monitoring crypto transactions after they occur.

By identifying platforms that convert local currency into digital assets and working with issuers such as Tether to disable the resulting tokens, US authorities can target both the entry points and the funds held in custody. The scale of Iran's crypto market has made those channels an increasingly important part of US sanctions enforcement. Chainalysis estimated that Iran's cryptocurrency ecosystem received more than $7.

Addresses linked to the Islamic Revolutionary Guard Corps (IRGC) accounted for about half of the country's crypto activity during the fourth quarter and received more than $3 billion over the year, the blockchain-analysis firm said. IRGC Dominates Iranian Crypto Ecosystem (Source: Chainalysis) By late May, Bessent said US authorities had seized or frozen nearly $1 billion in cryptocurrency connected to Iran through the wider campaign. The latest action builds on that effort and shows how Tether's control over USDT enables Washington to freeze funds held directly on public blockchain networks.

This shift continues to shape the digital-asset landscape, with analysts examining its near-term effects.