“U.S. rules, applied to companies in countries that never voted on them.” Extraterritorial sanctions — most commonly called “secondary sanctions” — are U.S. (or EU) sanctions measures that target non-U.S. persons and entities for engaging in transactions with U.S.-designated parties, even when the transaction has no U.S. nexus.
Executive Summary
Primary sanctions prohibit U.S. persons from transacting with sanctioned targets. Extraterritorial secondary sanctions go further: they threaten non-U.S. companies, banks, and governments with exclusion from U.S. markets, dollar clearing, and the global financial system if they do business with sanctioned parties — regardless of whether any U.S. person or territory is involved. This transforms U.S. sanctions from a domestic law into a de facto global regulatory standard, enforced through access to U.S. financial infrastructure. Secondary sanctions are the most contested tool of modern economic statecraft: for Washington, they are indispensable force multipliers; for Brussels, Beijing, Moscow, and most of the developing world, they represent unlawful extraterritorial overreach that undermines sovereign legal authority.
The Strategic Mechanism
- The dollar clearing leverage: Any bank processing dollar transactions goes through U.S. correspondent banks — placing those transactions within U.S. legal jurisdiction. A non-U.S. bank that processes a dollar payment involving a sanctioned entity can be cut off from dollar clearing — effectively cut off from the global financial system.
- SDN List and derivative exposure: OFAC’s Specially Designated Nationals (SDN) List prohibits any U.S. person from transacting with listed entities. Secondary sanctions extend this prohibition: non-U.S. companies doing “significant transactions” with SDN-listed parties face U.S. counter-measures.
- Sectoral sanctions: CAATSA (Countering America’s Adversaries Through Sanctions Act) sanctions target entire sectors of the Russian economy — defense, intelligence, energy — and include secondary sanctions provisions that expose non-U.S. arms purchasers and energy partners to U.S. counter-measures.
- Iran’s secondary sanctions architecture: The most extensive secondary sanctions regime in history — built through IFCA, CISADA, and reimposed under Trump in 2018 — effectively expelled Iran from the dollar system and pressured non-U.S. companies globally to exit Iranian contracts or lose U.S. market access.
- The blocking statute response: The EU’s Blocking Statute explicitly prohibits EU companies from complying with specific extraterritorial U.S. sanctions (currently Iran and Cuba) and authorizes “clawback” of damages suffered — creating a direct legal conflict that most multinational companies resolve by complying with U.S. sanctions regardless.
Market & Policy Impact
- CNAS’s 2025 sanctions year-in-review found that OFAC added nearly 1,000 new SDN designations related to Iran alone during 2025, with secondary sanctions provisions creating compliance obligations for European, Asian, and Gulf financial institutions.
- Chinese banks — including major state banks — have become more cautious in processing transactions involving Russian entities since secondary sanctions were intensified in 2024, demonstrating that secondary sanctions can change the behavior of ostensibly hostile-nation financial institutions.
- The SWIFT exclusion of Russian banks in 2022 demonstrated the extreme end of extraterritorial sanctions power: because SWIFT’s operating infrastructure has U.S. legal nexus, the exclusion effectively extended U.S. sanctions reach into the heart of European financial plumbing.
- Sanctions evasion infrastructure — front companies, third-country intermediaries, crypto transactions, and commodity swap arrangements — has grown substantially in response to secondary sanctions pressure, creating a shadow economy of sanctions-circumvention services.
- The Trump administration’s aggressive Iran secondary sanctions in 2025 forced European companies to make explicit binary choices between Iranian market access and U.S. market access — a choice that consistently resolved in favor of U.S. market access given the scale differential.
Modern Case Study: Russia Sanctions Evasion and the Limits of Secondary Pressure (2022–2025)
The post-2022 Russia sanctions regime — the most comprehensive ever assembled against a major economy — provided a real-world test of secondary sanctions’ limits. Despite SWIFT exclusion, SDN designations covering most major Russian banks, and secondary sanctions threatening non-U.S. companies transacting with Russia, Russia maintained access to international trade through a network of evasion mechanisms: a “shadow fleet” of 600+ tankers operating outside Western insurance and shipping systems moved Russian oil to India, China, and Turkey at discounts; Central Asian and UAE intermediaries re-exported Western goods to Russia through indirect channels; and Chinese banks (carefully) and Indian banks (more openly) continued processing Russian trade transactions. By 2025, Russian oil export revenues had recovered substantially from their 2022 lows, and the economy — while damaged — had not collapsed as the sanctions architects anticipated. The episode demonstrated both the extraordinary reach of extraterritorial secondary sanctions and the equally extraordinary adaptive capacity of sanctioned economies operating in a world that is no longer uniformly willing to enforce the Washington-led rules-based financial order.