International Sanctions: How Nations Use Economic Pressure

The Weapon That Doesn't Fire Bullets

On March 2, 2022, six days after Russia launched its full-scale invasion of Ukraine, the United States, European Union, United Kingdom, and other allies announced the exclusion of major Russian banks from the SWIFT international payment messaging system — the most sweeping financial sanctions applied to a major economy since the end of the Cold War. Within weeks, the ruble had lost nearly half its value, Russia's central bank had frozen foreign exchange reserves worth $300 billion held abroad, and Western companies were exiting the Russian market at unprecedented speed. Sanctions had become, if not a weapon of war, at least a weapon of economic warfare operating at civilizational scale.

Economic sanctions — measures that restrict trade, finance, travel, or other economic activities with a target country, entity, or individual — are now the primary coercive foreign policy tool short of military force. The United States alone maintained over 10,000 active sanctions designations as of 2024. Understanding how sanctions work legally and practically requires distinguishing between fundamentally different types of measures.

UN Security Council Sanctions vs. Unilateral Measures

The legal architecture of international sanctions has two distinct pillars with very different authority.

UN Security Council sanctions are legally binding on all member states under Article 25 and Article 41 of the UN Charter. Unilateral sanctions have no binding effect under international law on third countries — but their extraterritorial reach through secondary sanctions creates de facto compliance pressure regardless.

From Comprehensive Embargoes to Smart Sanctions

The evolution of sanctions design over the past three decades reflects painful lessons about collateral damage. Comprehensive trade embargoes against entire countries — the model applied to Iraq in the 1990s — caused severe humanitarian crises without reliably changing the behavior of governing elites. UN studies estimated that sanctions-related economic disruption contributed to hundreds of thousands of Iraqi civilian deaths during the 1990s, while Saddam Hussein's government remained in power throughout.

The concept of "smart" or targeted sanctions emerged from this experience. Rather than restricting trade with an entire economy, targeted sanctions focus on specific individuals and entities — designating them on sanctions lists that freeze their assets and prohibit transactions with them. The goal is to maximize pressure on decision-makers while minimizing harm to ordinary civilians.

The OFAC Specially Designated Nationals and Blocked Persons (SDN) list, maintained by the US Treasury's Office of Foreign Assets Control, is the most consequential targeted sanctions list in the world. Any person or entity on the SDN list is effectively cut off from the US financial system, and because the dollar is the world's primary reserve currency, SDN designation creates near-universal financial exclusion. As of 2024, the SDN list contains over 15,000 designations.

Secondary Sanctions: The Extraterritorial Reach

Secondary sanctions are the most legally controversial aspect of the US sanctions architecture. Primary sanctions prohibit US persons from conducting transactions with sanctioned targets. Secondary sanctions threaten non-US persons and entities with sanctions if they transact with US-sanctioned targets — essentially extending US law extraterritorially.

The EU, China, Russia, and other states have repeatedly objected that secondary sanctions violate international law by purporting to regulate conduct that occurs entirely outside US territory between non-US parties. The EU enacted a "blocking statute" (Council Regulation 2271/96) that prohibits EU entities from complying with certain US secondary sanctions laws. In practice, most European companies comply with US secondary sanctions anyway because losing access to the US financial system is an existential business risk.

Key Sanctions Programs

Three programs illustrate the range of US sanctions architecture and its limitations.

Iran: The US has maintained comprehensive sanctions against Iran since 1979. The Joint Comprehensive Plan of Action (JCPOA) of 2015 provided sanctions relief in exchange for limits on Iran's nuclear program. The Trump administration withdrew from the JCPOA in 2018 and reimposed maximum pressure sanctions. Iran responded by accelerating uranium enrichment. As of 2024, negotiations to restore the JCPOA remain stalled, and Iran's nuclear program has advanced significantly — suggesting that maximum pressure sanctions failed to achieve their stated strategic objective.

Russia 2022: Following the invasion of Ukraine, Western governments imposed the most comprehensive sanctions ever applied to a G20 economy. SWIFT exclusion, central bank reserve freezes, export controls on semiconductors and military technology, and individual designations affecting oligarchs and senior officials were implemented in coordinated waves. Russia's economy contracted in 2022 but proved more resilient than many economists predicted, aided by continued energy exports to non-sanctioning states and import substitution from China and other countries. Russia shifted trade flows rather than complying with Western demands.

Cuba: The US embargo against Cuba, codified in the Helms-Burton Act of 1996, is the longest-running comprehensive sanctions program in American history. Cuba has remained under the same government for over sixty years of embargo. The Helms-Burton Act's Title III, activated in 2019, permits US nationals (including Cuban Americans) to sue foreign companies for "trafficking" in property confiscated by the Cuban government — a provision the EU formally protested as violating international law.

Sanctions Effectiveness: The Research Is Mixed

Academic research on sanctions effectiveness presents a complicated picture. A frequently cited study by Hufbauer, Schott, and Elliott (1990) claimed a success rate of roughly one-third for sanctions programs studied. Subsequent reanalysis found significant methodological problems, with revised success rates closer to one-fifth. More recent meta-analyses suggest that sanctions rarely achieve major policy changes in target governments, particularly authoritarian regimes with limited accountability to economic suffering in the population.

• Sanctions are most effective when the target is a smaller economy heavily dependent on trade with the sanctioning coalition
• Sanctions imposed by a broad multilateral coalition outperform unilateral measures
• Targeted (smart) sanctions against elites may affect decision-making at the margins but are rarely decisive
• Comprehensive sanctions frequently harm civilian populations more than governing elites
• Sanctions create adaptation incentives — over time, target states develop workarounds, alternative trading partners, and domestic substitutes

Cryptocurrency and Sanctions Evasion

The rise of cryptocurrency has created new evasion vectors that regulators are actively working to close. Blockchain transactions are pseudonymous rather than anonymous, and sophisticated blockchain analytics firms can often trace fund flows. However, privacy coins (Monero), mixing services, and decentralized exchanges provide meaningful evasion capability for state-level actors with technical resources. North Korea's Lazarus Group is estimated to have stolen over $2 billion in cryptocurrency through hacks specifically designed to fund sanctions-evading activities. The Treasury has designated several cryptocurrency addresses and exchanges as SDNs — an attempt to apply traditional sanctions architecture to decentralized finance with only partial effectiveness. The evasion game has no obvious endpoint.