US President Donald Trump's recent threat to impose a 25 percent tariff on any country "doing business with" Iran has once again injected uncertainty into global trade and raised fresh concerns about the stability of China-US economic relations. While details of the proposed measure remain vague and its legal basis unresolved, the signal it sends is troubling: unilateral tariff threats risk undoing the hard-won progress achieved through dialogue and cooperation in recent months.

A trading partner of Iran, China's position on the issue is clear and consistent. As Foreign Ministry spokeswoman Mao Ning stated in response to questions on the matter on Tuesday, tariff wars have no winners, and China will firmly protect its legitimate and lawful rights and interests. This principled stance reflects not only China's own development experience but also a widely shared international consensus that trade barriers and coercive economic measures ultimately harm all sides.

The ambiguity of Trump's new tariff threat unsettles markets, complicates business planning and undermines confidence at a time when the global economy is already facing headwinds. According to the World Bank, the world is entering what may be the weakest decade for growth since the 1960s, with policy uncertainty and trade tensions among the headwinds to global growth.

For China and the United States, the timing of the threat is sensitive. Over the past months, both sides have made concerted efforts to stabilize their economic and trade ties. The outcomes of their five rounds of economic and trade talks have demonstrated that dialogue based on equality, respect and mutual benefit can yield tangible results.

Trump himself has also acknowledged the importance of the bilateral relationship, telling the media on Tuesday he believes China can open its markets further to US goods and reaffirming that he maintains a good relationship with his Chinese counterpart. The US administration should realize that cooperation, not confrontation, serves the fundamental interests of both countries, and China remains a major market to the US.

China's economic performance further highlights why confrontation through tariffs is counterproductive. Despite a complex external environment, the country's foreign trade in goods grew by 3.8 percent year-on-year to reach 45.47 trillion yuan ($6.51 trillion) in 2025, hitting a new record high. This resilience, despite some developed economies' "de-risking" or "decoupling" attempts, is driven by China's pro-trade policies, sizable domestic demand as well as its complete and upgrading industrial system that adapts to global needs. For US businesses, China has been and will continue to be an opportunity.

Attempts to use tariffs as tools of extraterritorial pressure run counter to the principles of international trade. Imposing penalties on third countries for their independent trade decisions infringes upon the legitimate rights of other nations and risks fragmenting the global trading system. The US approach only complicates the problem and will not bring more benefits to the US by giving it more leverage to use. Instead, it will introduce a dynamic that is more difficult to manage and create more variables beyond its control. It is an approach that will lead to a lose-lose situation, ultimately harming the interests of the US itself.

The legal uncertainty surrounding the tariffs within the US adds another layer of uncertainty. The US president's reliance on the International Emergency Economic Powers Act to impose broad tariffs is currently under scrutiny by the Supreme Court. A ruling against the Trump administration would not only curtail its authority to unilaterally raise tariffs but also expose it to substantial financial liabilities.

The progress achieved so far in stabilizing China-US economic and trade ties should be cherished, not squandered. Threats of new tariffs, citing whatever pretexts, risk reopening old wounds and sending the wrong signal to markets and the international community.

At this juncture, what the world needs most is stability and predictability. China and the US, as the world's two largest economies, bear a special responsibility in this regard. The US should work with China to maintain the momentum in their relations, move forward in the right direction, shorten the list of problems and lengthen the list of cooperation areas.

Bilateral economic and trade relations are finally experiencing a hard-earned respite from the trading of blows. The US side will only sabotage the development momentum of Sino-US economic and trade ties if it repeats its past mistakes. It should therefore refrain from resorting to its so-called "art of the deal", hallmarked by bluster, coercion, bullying and expectation management.