The détente between China and the United States was already fragile. Now it faces a new strain: the killing of Iran’s supreme leader, an American-backed strike that Beijing denounced as a blatant attempt at regime change.

中美之间本就脆弱的缓和关系如今又面临新的压力：美国支持的刺杀伊朗最高领袖行动被北京谴责为公然企图改变政权。

China has moved quickly to condemn the U.S. and Israeli strikes on Iran, with its top diplomat, Wang Yi, accusing both governments of assassinating another country’s leader and pledging to support Tehran’s sovereignty and security.

中国迅速谴责了美国和以色列对伊朗的袭击，中国最高外交官王毅指责两国政府暗杀他国领导人，并承诺支持伊朗的主权与安全。

The killing of Ayatollah Ali Khamenei came less than two months after American forces captured President Nicolás Maduro of Venezuela, another close partner of China. Together, the moves amount to a forceful display of American power against governments China has cultivated as part of its broader global strategy.

伊朗最高领袖哈梅内伊遇袭身亡距美军抓捕中国另一亲密伙伴委内瑞拉总统马杜罗还不到两个月。这两起行动共同构成美国力量的强力展示，直指中国全球战略中重点培育的政府。

Yet for Beijing, the question is how far to defend Iran, its closest diplomatic partner in the Middle East, without hurting its own economic interests or worsening tensions with the United States.

但对北京而言，核心问题是：在不损害自身经济利益、不加剧与美国紧张关系的前提下，应该在多大程度上捍卫其中东最密切的外交伙伴伊朗。

Already, the fighting has touched China directly. China’s foreign ministry said a Chinese national had been killed in Tehran and that Beijing was scrambling to evacuate thousands of its citizens.

战事已直接波及中国。中国外交部称，一名中国公民在德黑兰遇难，北京正紧急撤离数以千计的在伊公民。

一名工人周一在伊朗德黑兰空袭后拆除受损建筑的钢结构。

Beijing is likely troubled by the potential ripple effects of the American and Israeli strikes. China is the world’s largest importer of energy and Iran has already threatened to “set on fire” any ships traveling through the Strait of Hormuz, the waterway off Iran’s southern coast through which a fifth of the world’s oil travels. That could drive up prices and hit China’s economy.

美以发动的袭击带来的潜在连锁反应很可能让北京忧心忡忡。中国是全球最大能源进口国，而伊朗已威胁要“点燃”所有穿越霍尔木兹海峡的船只——这条伊朗南部沿海的航道承载着全球五分之一的石油运输。这可能推高能源价格，冲击中国经济。

There is also a quieter, domestic sensitivity to foreign-backed regime change. Xi Jinping, China’s leader, who has been in power since 2012 and is widely expected to begin a fourth term next year, presides over a political system that brooks no dissent. Under a Chinese state media article about Mr. Khamenei’s death, internet users congratulated Iranian residents and wondered aloud which leader might be next. Other comments suggesting that Iranians might have been celebrating have been censored.

此外，中国国内对于外国势力推动的政权更迭还有一层更隐秘的敏感情绪。自2012年执政、并被广泛预计将于明年开启第四个任期的中国领导人习近平领导着一个不容异见的政治体制。在中国官媒一篇关于哈梅内伊身亡的报道下，有网民向伊朗民众道贺，并大胆猜测下一个遇刺的领导人可能是谁。其他暗示伊朗民众可能在庆祝的评论已被审查删除。

Even as it navigates the various dimensions of the fallout from Iran, Beijing is likely most focused on its relationship with the United States.

即便要应对伊朗局势引发的多方面连锁反应，北京最关注的大概率仍是与美国的关系。

President Trump and China’s top leader, Xi Jinping, are weeks away from a summit in Beijing where they are expected to extend a trade truce between the world’s two-largest economies.

特朗普总统与中国最高领导人习近平几周后将在北京举行峰会，预计双方会延长这两大经济体之间的贸易休战协议。

The White House has said the meeting would take place from March 31 to April 2. China has yet to confirm details of the meeting and a foreign ministry spokeswoman said on Monday only that the two countries were in talks.

白宫已宣布会晤将于3月31日至4月2日举行。中国尚未确认会晤细节，外交部发言人周一仅表示，两国正就此沟通。

China could still consider canceling or postponing the meeting with Mr. Trump to show its displeasure with Washington’s use of military power against Iran.

中国仍可能考虑取消或推迟与特朗普的会晤，以此表达对华盛顿对伊朗动武的不满。

1989年，时任伊朗总统哈梅内伊访问中国，在北京会见了中国领导人邓小平。

Despite its sharp rhetoric over Iran, Beijing has strong incentives to keep its relationship with the United States on an even keel, analysts said. China wants Washington to agree to extend the trade truce, reduce its support for Taiwan and ease its restrictions on technology exports.

分析人士称，尽管在伊朗问题上言辞激烈，北京仍有强烈动机维持与美国关系的平稳。中国希望华盛顿同意延长贸易休战、减少对台支持，并放宽对华技术出口限制。

“Beijing cares much more about managing the United States than events in the Middle East,” said Julian Gewirtz, a former senior director for China and Taiwan Affairs at the National Security Council under President Joseph R. Biden Jr.

“比起中东局势，北京更在意如何处理对美关系，”拜登政府时期国家安全委员会中国与台湾事务前高级主任朱利安·格维茨表示。

The trip to China, which would be the first by an American president since Mr. Trump went in 2017, is seen as vital for maintaining the truce Mr. Xi and Mr. Trump reached last October in Busan, South Korea. Before that, China and the United States had engaged in a blistering trade war that sunk relations to their lowest point in more than 50 years.

此次访华将是特朗普2017年访华后美国总统首次访华，被视为维系习近平与特朗普去年10月在韩国釜山达成的休战协议的关键。此前，中美曾爆发激烈贸易战，双边关系跌至50多年来的最低点。

For China, postponing or canceling the summit would carry costs of its own. Mr. Trump has signaled a willingness to avoid confrontation with Beijing. His administration recently delayed announcing a package of arms sales to Taiwan, the self-governed island claimed by Beijing. It has eased restrictions on sales of advanced American chips to China. Mr. Trump refrained from mentioning China in last week’s State of the Union address, an unusual omission.

对中国而言，推迟或取消峰会自身也将付出代价。特朗普已释放出避免与北京对抗的意愿：其政府近期推迟公布对台军售计划（台湾是北京宣称拥有主权的自治岛屿），放宽了对华先进芯片的销售限制；上周国情咨文演讲中，特朗普未提及中国，这是一个不寻常的遗漏。

The legal landscape has also shifted in favor of Beijing, with the recent Supreme Court ruling that struck down many of President Trump’s tariffs. His new 10 percent tariff on global imports is beneficial to China.

法律层面也出现对北京有利的变化：美国最高法院近期的裁决推翻了特朗普多项关税政策；他新推出的全球进口商品10%关税政策对中国有利。

Walking away from the meeting could mean forfeiting that momentum.

放弃此次会晤可能意味着错失这一有利势头。

2017年，特朗普总统与中国国家主席习近平举行会晤。当时特朗普对中国进行了国事访问，虽然仪式隆重，但未取得实质性成果。

Beyond the summit, the conflict could reshape the strategic landscape in ways that benefit Beijing. Already, the United States has amassed the largest military force in the Middle East since the 2003 invasion of Iraq, deploying aircraft carrier strike groups and jets to the region. If that effort proves sustained, it could draw American attention and resources away from Asia.

除峰会外，这场冲突还可能重塑战略格局，给北京带来利好。美国已在中东集结了自2003年伊拉克战争以来规模最大的军事力量，向该地区部署了航母打击群与战机。若这一部署持续，可能会将美国的注意力与资源从亚洲转移。

Beijing may not be bothered if “the United States becomes bogged down in another unpopular war in the Middle East” that distracts it from China, Mr. Gewirtz said.

格维茨表示，如果“美国再次陷入一场不得人心的中东战争”，从而分散对中国的关注，北京或许并不会介意。

Beijing must also thread a diplomatic needle with Tehran. China has forged deep economic ties with many of the countries in the Gulf that Iran has launched attacks against in recent days, such as the United Arab Emirates and Saudi Arabia. Mr. Wang tried to strike a balance in his call with Iran’s foreign minister, Abbas Araghchi, calling on Iran to “pay attention to reasonable concerns of its neighboring countries.”

北京还必须在对伊朗外交方面拿捏分寸。中国与伊朗近期袭击的多个海湾国家（如阿联酋、沙特）有着深厚经济联系。王毅在与伊朗外长阿拉格齐通话时试图平衡立场，呼吁伊朗“重视邻国合理关切”。

Unlike the United States, which has formal defense commitments with dozens of allies, China has only one, with North Korea. Its partnerships with Iran and Venezuela are strategic, not military alliances.

美国与数十个盟友有正式防务承诺，而中国仅与朝鲜有此类承诺。中伊、中委关系是战略伙伴关系，而非军事同盟。

“Xi Jinping is unsentimental toward all of Beijing’s external relationships. He got to where he is based on his hardheadedness,” said Joe Webster, a senior fellow at the Atlantic Council, a Washington research group. “There’s not a large dividend for having a soft heart in the Chinese Communist Party.”

“习近平对北京所有对外关系都不感情用事，他能走到今天的位置，靠的是务实强硬，”华盛顿研究机构大西洋理事会高级研究员乔·韦伯斯特表示。“在中共内部，心软没什么好处。”

Beijing will instead likely continue to offer rhetorical support for Tehran while arguing that the United States is the greatest source of global instability. An editorial in the Global Times, a Chinese Communist Party tabloid, on Monday called on the international community to reject what it said was Washington’s bid to return the world to the “law of the jungle.”

因此，北京大概率会继续在口头上支持伊朗，同时指责美国是全球不稳定的最大根源。中共所有的小报《环球时报》周一发表社论，呼吁国际社会抵制华盛顿试图让世界重回“丛林法则”的行径。

Chinese analysts speaking to state media say the United States and Israel are sowing chaos in the Middle East and have set a dangerous precedent by assassinating Mr. Khamenei.

中国官媒援引的分析人士称，美以两国正在中东播撒混乱，且暗杀哈梅内伊开创了危险先例。

Still, the strikes on Iran have laid bare the gulf between the two superpowers’ military capabilities. Despite its rapid investment in recent decades, China does not possess an army like the United States that can project power in any part of the world.

但对伊朗的袭击也暴露了两个超级大国军事实力的差距。尽管中国近几十年快速投入军力建设，却尚未拥有像美国那样、能在全球任何地方投射力量的军队。

That rankles Beijing, said Dylan Loh, an expert on Chinese foreign policy at Nanyang Technological University in Singapore, because it means no country — not even China — can stop the United States from taking whatever action it wants.

新加坡南洋理工大学中国外交政策专家骆明辉表示，这让北京感到刺痛——因为这意味着没有任何国家能阻止美国为所欲为，哪怕中国也不例外。

“The demonstration of raw, hard power is something that will worry Beijing,” Mr. Loh said.

“这种赤裸裸的硬实力展示，会让北京感到担忧，”骆明辉说。