China vows to defend its interests as expanded Iran sanctions test how far Trump will confront Beijing
BEIJING/WASHINGTON — China has warned that it will take necessary steps to protect its legitimate interests after the United States widened its economic campaign against Iran and threatened consequences for foreign companies and countries that continue doing business with Tehran, setting up a potentially much larger confrontation over whether Washington can enforce Iran's isolation without directly challenging Beijing. The Trump administration on Monday launched what Treasury Secretary Scott Bessent called “Operation Economic Outcast,” blacklisting more than 60 Iran-linked individuals, entities and vessels and preparing expanded secondary sanctions across sectors including shipping, technology, aviation, gold and digital assets. Beijing's response turns what Washington presented as an offensive against Iran into an early test of U.S. leverage over the world's second-largest economy, because Chinese refiners, traders and shipping networks remain deeply embedded in Tehran's surviving international commerce.
China's Foreign Ministry had warned even before the full sanctions package was announced that Beijing would closely monitor Washington's actions and “do what is necessary” to protect Chinese rights and interests. After the measures were unveiled, Beijing rejected unilateral sanctions and what it regards as U.S. extraterritorial jurisdiction, while Chinese entities were among those caught in Washington's latest action. The language is consistent with China's longstanding opposition to American secondary sanctions, but the stakes are considerably higher now because Bessent has explicitly warned Iran's trading partners that Washington intends to make continued economic relations with Tehran increasingly costly.
The critical question is enforcement. Treasury says Operation Economic Outcast will seek to isolate Iran from the global financial system and target the networks allowing Tehran to generate and move revenue, while Bessent has warned foreign governments and businesses that they will have time to reduce economic exposure before further measures arrive. But the administration's ability to turn that threat into genuine economic isolation depends heavily on what it does about China. Reporting on the new campaign estimates that China purchases around 90% of Iran's exported oil, making Beijing not merely another Iranian trading partner but the central external market sustaining Tehran's petroleum revenues.
Washington has already demonstrated that Chinese involvement is not automatically protected. Earlier U.S. measures targeted Chinese independent refiners and shipping networks accused of handling Iranian crude, including Hengli Petrochemical's Dalian refinery and vessels linked to the so-called shadow fleet used to move sanctioned oil. Treasury said in April 2025 that its sanctions against Chinese importers formed part of a broader effort to reduce Iranian petroleum revenue, and subsequent actions expanded pressure on China- and Hong Kong-linked shipping companies. The new campaign therefore builds on an existing sanctions architecture rather than beginning from zero, but targeting individual companies is substantially different from imposing measures powerful enough to force China's wider energy and financial system to abandon Iranian trade.
That distinction creates the central contradiction inside Washington's strategy. Secondary sanctions derive much of their power from access to the U.S. dollar, American banks and the enormous U.S. market: foreign companies can be forced to choose between relatively limited business with Iran and access to the much larger American financial system. That calculation can be devastating for smaller firms or countries dependent on U.S. markets. Applying the same pressure aggressively to major Chinese institutions, however, risks retaliation from an economy with the scale to impose meaningful costs of its own, particularly while Washington and Beijing are trying to preserve a fragile trade understanding. The Financial Times reported on Tuesday that Beijing could retaliate if Washington aggressively expands Iran-related secondary sanctions against Chinese companies.
The first sanctions package may reveal that Washington understands the danger. Although Chinese and Hong Kong entities were included among the targets, reporting on the announcement noted that the administration stopped short of immediately targeting the major Chinese financial institutions that could represent a far more consequential pressure point in Iran's trade. The Wall Street Journal reported that the initial package avoided directly provoking Beijing, while Axios noted that the administration has yet to impose the full secondary-sanctions threat against Iran's largest foreign economic partners. That suggests Operation Economic Outcast may unfold progressively, allowing Washington to threaten escalation while preserving room for diplomacy with governments whose cooperation would be essential to making the strategy work.
The timing makes China particularly sensitive. Trump has spent months combining pressure with negotiation toward Beijing, and another major sanctions confrontation could spill into trade, tariffs, technology restrictions and wider bilateral relations. Iran therefore creates a difficult strategic choice: Washington can impose penalties aggressively enough to threaten China's access to U.S. finance and demonstrate that its sanctions have no exemptions, or it can calibrate enforcement to avoid a confrontation with Beijing — but doing so could allow Iran's largest remaining oil market to continue functioning and weaken the very economic isolation Bessent says Washington intends to create.
Beijing has reasons of its own to resist. Discounted Iranian crude gives Chinese buyers access to energy supplies outside Western-controlled trading channels, while maintaining commercial relations with Tehran reinforces China's broader opposition to unilateral U.S. sanctions and American use of the dollar-based financial system as a geopolitical instrument. China has repeatedly described Washington's extraterritorial sanctions as “long-arm jurisdiction,” arguing that American domestic law should not determine lawful commercial relations between Chinese and Iranian entities. For Beijing, therefore, compliance would carry consequences beyond Iran: accepting Washington's authority to dictate Chinese trade with Tehran could establish precisely the precedent Chinese policymakers have spent years opposing.
Iran's response adds another layer of pressure. Tehran said Tuesday it was prepared for the expanded sanctions and threatened retaliation, while Iranian officials have warned that further economic pressure could affect energy flows through the Gulf. Reuters reported that Iran says it has prepared mechanisms to withstand intensified sanctions after years of operating under U.S. restrictions. The effectiveness of that resistance will depend partly on whether Iran can continue selling oil and accessing payment channels through partners willing to tolerate U.S. pressure — which again places China near the centre of the confrontation.
The new sanctions also arrive as military pressure has failed to produce a decisive end to the conflict. Washington is increasingly turning toward financial isolation as another instrument against Tehran, while regional mediation efforts continue and the Strait of Hormuz remains strategically central to global energy markets. That means the economic campaign is not separate from the war but increasingly one of its principal fronts: instead of relying solely on military pressure against Iran, the United States is attempting to force companies and governments outside the battlefield to choose between maintaining economic ties with Tehran and preserving unrestricted access to American finance.
For many countries and private companies, Washington may possess enough leverage to make that choice straightforward. China is different. Its enormous domestic market, state-controlled financial institutions, alternative payment mechanisms and ability to retaliate economically give Beijing substantially greater room to resist American pressure than most Iranian trading partners possess. At the same time, China's economy remains deeply connected to Western markets and dollar-based finance, meaning even Beijing cannot simply ignore every American sanction without cost. The confrontation is therefore less about whether either side has leverage than about which government is willing to absorb greater economic damage to enforce its position over Iran.
That is what transforms China's warning from routine diplomatic language into a potentially decisive test of Trump's strategy. Washington can announce the toughest Iran sanctions regime it wants, but Iran cannot be economically isolated while its principal oil customer continues absorbing most of the exports the United States is trying to eliminate. If Trump ultimately sanctions major Chinese banks, refiners or trading networks, Operation Economic Outcast could evolve into a direct U.S.-China economic confrontation. If Washington avoids those targets to preserve relations with Beijing, Tehran may retain one of the most important lifelines the sanctions campaign was designed to close.
The next phase will therefore reveal more about the strength of the sanctions than Monday's initial blacklist. Bessent has promised additional measures and a defined period for foreign partners to adjust their Iran exposure, meaning companies and governments will soon have to determine whether Washington is prepared to enforce its threats against economically significant players rather than only smaller intermediaries. Beijing has now supplied its answer in advance: China does not intend to accept U.S. sanctions against its legitimate economic interests without resistance.