After stepping back this month from an escalating and dangerous war of tariffs, the United States and China are now threatening to undermine their uneasy truce.

中美两国本月暂时叫停了不断升级的关税战，但如今双方又有可能打破这一脆弱的休战状态。

On May 12, the countries announced after weekend meetings in Geneva that they would suspend most of their recently imposed tariffs. Since then, however, both governments have shown that they are still prepared to wield controls over critical exports as weapons against one another, with moves that are potentially even more damaging to trade and global supply chains.

5月12日，两国在日内瓦举行周末会谈后宣布，将暂停大部分近期加征的关税。但此后，双方政府的一系列举措表明，它们仍然准备将关键产品的出口管制作为相互攻击的武器，这些举措可能对贸易和全球供应链造成更严重的破坏。

China has restricted its exports of rare earth magnets, which are crucial for cars, semiconductors, aircraft and many other applications. Close to 90 percent of the world’s rare earth metals, including magnets, are produced in China.

中国已限制稀土磁铁的出口，这种材料对汽车、半导体、飞机等众多领域至关重要。全球近90%的稀土金属（包括磁铁）产自中国。

And the United States on May 13 banned the latest semiconductors from Huawei, a Chinese electronics giant. Then on Wednesday, President Trump suspended the shipment of American semiconductors and some aerospace equipment needed for China’s commercial aircraft, the C919, a signature project in China’s push toward economic self-reliance.

美国则于5月13日宣布针对中国电子巨头华为最新款半导体产品的禁令。随后周三，特朗普总统又下令暂停向中国商用飞机C919供应所需的美制半导体及部分航空设备——C919是中国推动经济自主的标志性项目。

The increasing use of export controls by both countries amounts to supply chain warfare, interrupting the flow of key components that the other country must have to operate huge industries that employ large numbers of workers.

两国对出口管制手段的使用越来越多，已演变为供应链战争，切断了对方涉及大量就业的庞大产业运行所需关键部件的流通。

Last week, Ford Motor temporarily closed a factory in Chicago that makes Ford Explorer sport utility vehicles after one of its suppliers ran out of the magnets. In most new cars, the magnets are used in dozens of electric motors that operate brake and steering systems, fuel injectors and even power seats.

上周，由于一家供应商的稀土磁铁库存耗尽，福特汽车临时关闭了位于芝加哥的一家生产探险者SUV的工厂。在多数新车中，磁铁会用于数十个电机，驱动刹车系统、转向装置、燃油喷射器，甚至电动座椅。

中国赣州的一家稀土磁体工厂。

On Monday, China granted some export licenses for rare earth magnets to be shipped to the United States and Europe, according to two industry executives who spoke on the condition of anonymity to discuss a sensitive matter. But many more factories in both regions will have to close in the coming days and weeks if China does not resume full exports of rare earth metals, corporate executives and business leaders said.

据两名因话题敏感而要求匿名的行业高管透露，本周一，中国向部分对欧美出口稀土磁铁的企业发放了许可证。但企业高管和商界领袖警告，若中国不全面恢复稀土金属出口，未来数周欧美将有更多工厂被迫关闭。

“Hundreds of E.U. companies are impacted, and we expect that this may lead to production stoppages already this week for some companies,” said Jens Eskelund, the president of the European Union Chamber of Commerce in China.

中国欧盟商会主席彦辞表示：“数百家欧盟企业受到影响，我们预计部分企业本周就可能停产。”

American companies are feeling the effect even more. Several companies in Europe, including Volkswagen, were granted permission by Beijing to continue procuring rare earth magnets soon after China began enforcing export controls on them in April. American companies have been juggling factory schedules, reassigning their dwindling magnet supplies to continue making their most profitable products.

美国企业受到的影响更为显著。自4月中国实施稀土磁铁出口管制以来，包括大众汽车在内的多家欧洲企业迅速获得采购许可，而美国企业则不得不调整生产计划，将日益减少的磁铁库存优先用于利润最高的产品。

A Ford spokesman confirmed that the Explorer factory had been closed last week because of a disruption in rare earth magnet supplies, but said that it had reopened this week. Ford had been planning to not run the factory for a week anyway in the coming months, and shifted that down time to last week when the magnet supply ran short, he said.

福特发言人证实，生产探险者的工厂上周因稀土磁铁断供而停产，但本周已恢复运转。他的解释是福特原本就计划在未来几个月内停产一周，因此将停机时间提前至磁铁短缺的上周。

The agreement reached in Geneva by U.S. and Chinese officials to de-escalate their confrontation over tariffs has been cheered by investors. The two sides said they would take a 90-day pause on tariffs and set up working groups of top officials to try to reach agreements on trade.

中美官员在日内瓦达成的缓和关税对抗的协议曾令市场为之振奋。双方同意设置90天的关税休战期，并组建高级别工作组推进贸易谈判。

That made the timing of the U.S. Commerce Department’s decision a day later to ban Americans from using or financing Huawei artificial intelligence chips noteworthy. The department contended that the A.I. chips were based on a prohibited export of American technology, which Huawei has denied.

正因为如此，当美国商务部在协议达成的次日宣布禁止美国人使用或资助华为人工智能芯片的决定，这一时机格外引人注目。商务部称，这些人工智能芯片是基于违规获取的美国技术，而华为对此予以否认。

The restrictions were the latest in a long series of American blows aimed at Huawei, which is one of China’s best-known success stories. Its hundreds of thousands of workers produce everything from cellphone base stations to autonomous driving systems for cars.

这一限制措施是美国针对华为一连串打击中的最新一次。华为是中国最具代表性的成功企业之一，拥有数十万员工，产品涵盖从手机基站到汽车自动驾驶系统等多个领域。

Chinese officials have reacted with growing anger at the U.S. use of export controls.

中国政府对美方滥用出口管制的愤怒持续升级。

“China once again urges the U.S. to immediately correct its wrong practices, stop discriminatory restrictive measures against China, and jointly maintain the consensus reached at the Geneva high-level talks,” He Yongqian, the Ministry of Commerce spokeswoman, said at a news briefing on Thursday.

中国商务部新闻发言人何咏前周四在新闻发布会上表示：“中方再次敦促美方，立即纠正错误做法，停止对华歧视性限制措施，共同维护日内瓦高层会谈共识。”

American restrictions on sales to COMAC, a state-owned enterprise, represent a setback to the Chinese government’s long-term project to shed its dependence on Boeing and Airbus. The C919 aircraft is heavily dependent on American and European components, with the company’s miles-long complex of hangars and design labs in Shanghai mainly installing components from foreign companies in Chinese-built air frames.

美国对国有企业中国商飞的销售限制，意味着中国政府摆脱波音和空客依赖的长期目标遇挫。C919飞机严重依赖欧美零部件，其位于上海的庞大机库和设计实验室网络，主要负责将外国企业生产的零部件安装到国产机身里。

COMAC did not respond to a phone call and fax for comment.

中国商飞未对请求置评的电话和传真作出回应。

工人正在组装C919客机的发动机部件，2018年摄于中国沈阳。

In a reply to questions early Thursday, Kush Desai, a White House spokesman said: “The Geneva agreement was a major first step towards securing a final, comprehensive trade deal with China. Discussions continue, and the administration is monitoring compliance with the agreement.”

白宫发言人库什·德赛于周四早间回应提问时表示：“日内瓦协议是达成最终全面对华贸易协定的重要第一步。磋商仍在继续，政府正在跟进协议履行情况。”

The United States has been gradually tightening export controls on semiconductors for a decade, contending that China has used American computer chip technology to improve a wide range of military hardware. Chinese government officials and industry executives have denied this, and contend that the United States is trying instead to limit China’s economic development.

十年来，美国逐步收紧半导体出口管制，声称中国利用美国芯片技术升级各类军事装备。中国政府和企业高管对此予以否认，反指美国实为企图遏制中国的经济发展。

Two days after Mr. Trump imposed steep tariffs on April 2 on imports from China and many other countries, China imposed its own export controls on some kinds of rare earths and heat-resistant magnets made from them.

特朗普于4月2日对中国及多国商品加征高额关税后仅两天，中国就对部分稀土及相关耐热磁铁实施了出口管制。

The Geneva trade agreement had also called for China to “adopt all necessary administrative measures to suspend or remove the non-tariff countermeasures taken against the United States since April 2, 2025.”

日内瓦贸易协议还要求中国“采取一切必要行政措施，暂停或取消自2025年4月2日起对美实施的非关税反制措施”。

But China’s Commerce Ministry has contended that rare earths have military applications, and it has avoided describing its export controls as a trade countermeasure. Although most rare earth magnets are used in civilian industries, they are also essential for electric motors in advanced fighter jets and the guidance systems of intercontinental ballistic missiles.

但中国商务部坚称稀土具有军事用途，拒绝将出口管制定性为贸易反制。尽管大多数稀土磁铁用于民用领域，但它们在先进战斗机的电机和洲际弹道导弹制导系统中同样不可或缺。

“It is a common international practice to impose export controls on items with obvious dual-use military and civilian attributes,” Ms. He said on Thursday.

何咏前在周四表示，“对具有明显军民两用属性的物项，实施出口管制是国际通行做法。”

Experts in China have begun defending export controls on rare earth magnets as appropriate while the United States maintains export controls on semiconductors.

中国专家已开始为稀土磁铁出口管制辩护，指出美国持续实施半导体管制在前，中国举措属合理应对。

“China sees export controls on rare earths as a counterstrike to U.S. export controls on semiconductors,” said Zhu Ning, deputy dean at the Shanghai Advanced Institute of Finance.

上海高级金融学院副院长朱宁指出：“中国将稀土出口管制视为对美国半导体管制的反制。”

Yet if China maintains export controls on rare earths, many multinational companies may conclude that their supply chains are too reliant on China, Mr. Eskelund said. “The risk of production stoppages due to export controls will only increase calls in Europe for de-risking from China.”

然而中国欧盟商会主席彦辞表示，若中国持续实施稀土出口管制，或将促使更多跨国企业重新评估对中国供应链的依赖，“出口管制导致的生产中断风险，只会加剧欧洲推进去中国风险的呼声。"

The question now is how much longer both sides maintain their export controls.

当前的关键问题是，双方的出口管制措施还将持续多久。

“It would be unfortunate if one or both sides overestimates its own leverage and feels like it needs to prove that to the other side,” said Chris Adams, a former Treasury official who is now a partner at the Covington and Burling law firm.

曾任美国财政部官员、现为科文顿律师事务所合伙人的克里斯·亚当斯指出：“若一方或双方高估自身筹码，并试图向对方证明这一点，都将导致双输局面。”