EU joins U.S. economic sanctions as Seoul weighs Hormuz role

The European Union has formally joined Washington's Operation Economic Outcast, a U.S.-led campaign of economic sanctions meant to cut Iran from the global financial system, while South Korea weighs possible military support to reopen the Strait of Hormuz. Treasury Secretary Scott Bessent hailed the EU move as allies intensify pressure on Tehran.

Key Takeaways

• Brussels endorsed Operation Economic Outcast on Aug. 31, backing extra economic pressure on Iran.
• Bessent expects new U.S. secondary sanctions weekly, starting with banks that handle Iran-linked funds.
• The late-August campaign targets digital assets, tech procurement, gold, aviation and shipping.
• South Korea is reviewing military options for Hormuz; Seoul says no decision has been made.
• Iran denounced the EU's move as "economic terrorism" and warned partners against joining.

What did the EU and South Korea actually decide?

According to CNBC, the EU formally joined the U.S.-led sanctions campaign against Iran. In an Aug. 31 statement, Brussels supported efforts to curb Tehran's "destabilizing activities" and resume peace talks, including through Operation Economic Outcast.

Bessent praised the bloc in a Thursday social media post, saying the world would not stop "until every remaining financial lifeline has been severed." Separately, South Korea is weighing options that include military assistance to help reopen the Strait of Hormuz to commercial shipping, Reuters reported, citing the presidential office.

Seoul denied local media claims that a deployment decision is already locked in. Yonhap quoted officials saying "details related to the issue have yet to be decided," even as some outlets reported troops could head to the Gulf before year-end.

How are economic sanctions supposed to work this time?

The Trump administration launched Operation Economic Outcast in late August. It aims to sever Iran's access to digital assets, advanced technology procurement, gold reserves, commercial aviation and shipping—areas closely watched in our Future Tech & AI Wonders coverage of dual-use finance and tech controls.

Bessent told Reuters the Treasury is likely to unveil new secondary sanctions weekly, with an initial focus on banks. After penalties on UAE branches of Egypt's Banque Misr over alleged Iran links, he said the next step may be cutting an institution entirely from the dollar system. "You're going to see a lot more of these every week," he said. "There can be no leakage."

The EU already runs its own sanctions regime on Iran's nuclear and ballistic missile programs and its military support for Russia. China was Iran's largest trading partner before the war, buying around 90% of Tehran's sanctioned crude exports.

Why does this raise the stakes beyond finance?

Military hostilities intensified recently. The U.S. struck Iranian military targets after attacks on ships and American forces; Iran fired missiles at U.S. bases. Hormuz, once a chokepoint for roughly a fifth of global oil flows, remains subdued amid periodic Iranian strikes on the southern shipping lane.

U.S. Central Command said Friday it has redirected 87 commercial vessels, disabled three and boarded two under a naval blockade of Iranian ports. Iran's foreign ministry spokesperson Esmail Baghaei blasted the EU endorsement as surrender to U.S. "economic terrorism."

In a Guardian analysis, Sina Toossi argued the "economic D-day" approach risks further escalation: Iranian officials have called participation an "act of war," while Beijing has ordered firms not to comply with some U.S. measures targeting Chinese buyers of Iranian oil. Washington is betting Iran's economy breaks first; Tehran is betting U.S. tolerance for costs breaks first.