When U.S. Treasury Secretary Scott Bessent launched Operation Economic Outcast against Iran, he promised to target its “enablers” and “sever every economic lifeline that sustains this tyrannical regime until Tehran stands alone.” Washington has since sanctioned everything from foreign banks to Iranian airlines. Yet it has spared one of the most prominent institutions ever accused of helping Iran evade U.S. sanctions: Turkey’s state-owned Halkbank. This Iranian lifeline, too, must be severed.

In one of the biggest sanctions-evasion cases ever, U.S. prosecutors charged in 2019 that, between 2012 and 2016, Halkbank violated U.S. sanctions by transferring roughly $20 billion in Iranian oil proceeds into gold and cash while disguising the transactions as legitimate food trade. Washington spent years prosecuting Halkbank, only to settle the case through a deferred prosecution agreement in March and drop it in June without the bank paying a fine or admitting to any wrongdoing.

Halkbank’s reprieve, according to Justice Department filings, was tied to Turkey’s help in brokering the October 2025 ceasefire in Gaza. With this trade, Washington told Ankara that it can buy immunity from U.S. sanctions enforcement and signaled to Tehran that Turkish banks remain a safe channel for its money.

Turkey and Iran got the message. A financial architecture like the one that enabled Halkbank’s sanctions evasion once again operates from Turkey.