On August 24, U.S. Treasury Secretary Scott Bessent held a press conference announcing that the United States had officially launched a new round of sanctions against Iran. Through multifaceted and far‑reaching restrictive measures, it seeks to subject Iran to full‑scale “economic isolation” and continues to escalate its maximum‑pressure campaign against the country.
In a tough‑toned statement at the press conference, Bessent said if relevant countries fail to comply with U.S. sanctions on Iran, the U.S. Department of the Treasury will impose unilateral punitive measures. Observers widely interpret this remark as a signal that Washington may trigger secondary sanctions against third‑party countries that do not take part in its sanctions on Iran. (Secondary sanctions, also known as second‑tier sanctions, are extraterritorial jurisdictional measures applied by the United States to non‑U.S. persons under its domestic law, designed to compel third parties to abide by its sanction resolutions. Primary sanctions restrict transactions only between U.S.‑based entities and targeted parties—Ed.)
Addressing the new round of unilateral U.S. sanctions and potential extraterritorial pressure, Lin Jian, a spokesperson for China’s Ministry of Foreign Affairs, gave a clear response at a regular press briefing in Beijing on August 25, stressing that China firmly opposes illegal unilateral sanctions that lack basis in international law and have not been authorized by the UN Security Council.
“Economic warfare and maximum pressure do nothing to resolve problems; they only further fuel conflicts, cause risk spillovers, disrupt global economic and financial order, and impair the legitimate rights and interests of other countries. The pressing priority is to de‑escalate the situation and return to the track of dialogue and negotiation at an early date,” he said.
Lin emphasized that China’s cooperation with Iran has always been conducted within the framework of international law and should not be disrupted or undermined. He added that China is closely following relevant developments and will take all necessary measures to resolutely safeguard its own rights and interests.
These developments raise a question that extends far beyond China, Iran, or the immediate crisis: When one country imposes sanctions unilaterally, what legal or moral obligation do other sovereign countries have to comply, particularly when they are not parties to the conflict and the measures have not been authorized by the United Nations Security Council?
The U.S. example
During the past decade, the United States has increasingly used sanctions, export controls, tariffs, financial restrictions, investment prohibitions, technology controls and entity designations as central instruments of foreign policy. These measures have targeted governments, corporations, banks, ships, universities, research institutions, political officials, business executives and private individuals across many jurisdictions.
Washington considers this system an alternative to military force and a means of defending national security, countering terrorism, preventing nuclear proliferation, punishing aggression, combating human rights abuses and disrupting illicit finance. Critics see something different: a system through which one country uses its control over global finance, technology and trade to impose policies that the international community has not collectively authorized.
The United States does not have a single unified sanctions institution. Its economic restrictions form an overlapping network.
The president usually provides overall direction through executive orders, emergency declarations, national security memoranda, and delegated statutory authority. Congress can establish mandatory sanctions, define targeted conduct, limit presidential waiver authority, or require periodic reports and designations.
The Treasury Department’s Office of Foreign Assets Control, commonly known as OFAC, administers many financial sanctions. It may block assets, prohibit transactions, designate individuals and entities, issue licenses, and maintain the Specially Designated Nationals and Blocked Persons List.
The State Department makes or participates in certain terrorism, nonproliferation, human rights, visa, energy and foreign policy designations. It also coordinates diplomatic efforts to encourage allies and other countries to adopt similar restrictions.
The Commerce Department’s Bureau of Industry and Security administers the Export Administration Regulations. These rules govern certain exports, reexports and in-country transfers of American technology, software, dual-use products and some foreign-produced items derived from controlled American technology.
The Defense Department maintains lists of foreign military-linked companies and provides assessments that may influence investment restrictions, procurement exclusions, or other government action. A Defense Department listing is not necessarily identical to an OFAC asset freeze, but it can become part of a broader sanctions or restrictions process.
The Office of the United States Trade Representative administers trade actions, including tariffs and restrictions imposed under American trade statutes. These may have different legal foundations from traditional sanctions but can serve comparable strategic purposes. Although not every tariff or export control is technically a sanction, the measures increasingly operate as part of an integrated system of economic statecraft.
The result is an expansive architecture in which sanctions, tariffs, export controls, investment restrictions, procurement rules, technology prohibitions, banking regulations and visa restrictions increasingly reinforce one another.
Must other countries comply?
Other countries do not have a general legal obligation to comply with unilateral American sanctions.
They are required to implement binding UN Security Council decisions. They must also follow sanctions enacted under their own national laws or, in the case of European Union members, relevant EU regulations. But a U.S. statute or executive order does not automatically become law in Brazil, China, South Africa, India, Indonesia or any other sovereign country.
A foreign person may nevertheless come within U.S. jurisdiction when a transaction has a genuine American connection. This can occur when a payment passes through a U.S. bank or dollar-clearing institution, a transaction involves an American citizen or company or property located in the United States, a foreign company operates through an American subsidiary, a product contains controlled U.S.-origin components, and a foreign-made product is produced with specified American technology, or when conduct is designed to cause an American person to violate U.S. law.
These jurisdictional connections can be complex. The use of the U.S. dollar is particularly important because many dollar-denominated transactions pass through correspondent banks in the United States, even when the buyer, seller and goods are all located elsewhere.
But where two foreign parties conduct a lawful transaction entirely outside the United States, using non-American institutions and products, the American claim to regulate that transaction directly becomes substantially more controversial.
Foreign companies often follow U.S. sanctions anyway. They do so because access to American banks, capital, consumers, investors, software, semiconductors, equipment, insurers and professional services is too valuable to risk.
The resulting compliance is real, but its legal character must be understood correctly. It is frequently not compliance with an internationally binding rule. It is a commercial decision made under threat of economic exclusion.
This distinction between legitimacy and power is essential. The United States may possess the financial, technological and commercial power to compel foreign governments and companies to follow its policies. But the ability to impose a policy does not automatically give that policy international legal authority. Sanctions should be judged by their legal basis, proportionality, effectiveness, humanitarian consequences and contribution to a peaceful resolution.
International disputes should ultimately be resolved through dialogue, negotiation and political settlement. Sanctions may sometimes support diplomacy, but they should never become a permanent substitute for diplomacy or a form of economic warfare without accountability, limits or a credible path to peace. BR
