The world economy was already grappling with a perplexing assortment of variables, from geopolitical conflicts and a slowdown in China to the evolving complexities of climate change. Then, President Trump unleashed a plan to uproot decades of trade policy.

从地缘政治冲突、中国经济放缓到气候变化日益复杂的演变，世界经济已经在努力应对各种令人困惑的变数。现在特朗普总统又发布了一项计划，将数十年来的贸易政策彻底颠覆。

In starting a process to impose so-called reciprocal tariffs on American trading partners, Mr. Trump increased volatility for international businesses. He broadened the scope of his unfolding trade war.

在启动对美国贸易伙伴征收所谓对等关税的过程中，特朗普给跨国企业增加了不确定性。他扩大了正在展开的贸易战的范围。

In basic concept, the argument for reciprocal tariffs is straightforward: Whatever levies American companies face in exporting their wares to another country should apply to imports from that same country. Mr. Trump has long championed this principle, presenting it as a simple matter of fairness — redress to the fact that many American trading partners maintain higher tariffs.

就基本概念来说，实施对等关税的理由很简单：美国企业在向其他国家出口商品时所面临的关税应该适用于来自该国的进口商品。特朗普长期以来一直主张该原则，将其作为事关公平的简单问题——这是针对许多美国贸易伙伴维持了较高关税这一事实做出的修正。

Yet in practice, calculating individual tariff rates on thousands of products drawn from more than 150 countries poses a monumental problem of execution for a vast range of companies, from American manufacturers dependent on imported parts to retailers that buy their goods from overseas.

然而，在实践中，分别计算来自150多个国家的成千上万种产品的关税税率，对于众多企业来说——从依赖进口零部件的美国制造商，再到从海外采购商品的零售商——执行起来存在巨大的困难。

“It’s potentially a herculean task,” said Ted Murphy, an international trade expert at Sidley Austin, a law firm in Washington. “For every widget, every tariff classification, you can have 150 different duty rates. You’ve got Albania to Zimbabwe.”

华盛顿盛德律师事务所的国际贸易专家泰德·墨菲表示，“这可能是一项艰巨的任务。对于每个小零件、每个税目，都可能有150个不同的税率。从字母A开头的国家到字母Z开头的国家，你都要去计算。”

上个月，哥伦比亚卡塔赫纳一家工厂里的缝纫女工。特朗普威胁要对从哥伦比亚等国进口的产品征收关税，这样一来，将工厂迁出中国对企业来说就没那么有价值了。

The order that Mr. Trump signed on Thursday directed his agencies to study how to proceed with reciprocal tariffs. That raised the risk of increasing costs for American consumers at a time of deepening concern over inflation, challenging the president’s own vows to bring down prices on groceries and other everyday items. And that heightened the possibility of greater delay from the Federal Reserve in lowering borrowing costs.

根据特朗普上周四签署的命令，他授意手下部门要研究如何推进对等关税。在对通货膨胀的担忧日益加深之际，这增加了美国消费者成本上升的风险，同时也对特朗普关于降低食品杂货和其他日常用品价格的承诺构成了挑战。而且，这还增加了美联储在降低借贷成本方面进一步推迟行动的可能性。

It also hastens the diminishing of the world trading system, which has long been centered on multilateral blocs and adjudicated by the World Trade Organization. Mr. Trump is aiming to advance a new era in which treaties give way to country-to-country negotiations amid a spirit of nationalist brio.

它还加速了世界贸易体系的衰落，该体系长期以来一直以多边集团为中心，并由世界贸易组织负责争端的裁决。特朗普的目标是推动一个新时代的到来，在这个时代里，随着民族主义的热情高涨，贸易条约将让位于国与国之间的谈判。

The transition threatens to add to strains on global supply chains after years of upheaval. International businesses have contended with an unfolding trade war between the world’s two largest economies, the United States and China. They have confronted impediments to passage through the Suez and Panama Canals, sending shipping prices soaring.

这一转变可能会加剧本已经历多年动荡的全球供应链的压力。跨国企业一直在应对美国和中国这两个全球最大经济体之间正在展开的贸易战。它们还面临通过苏伊士运河和巴拿马运河的通行障碍，导致航运价格飙升。

Now, Mr. Trump has presented them with another formidable puzzle.

现在，特朗普又给他们出了一道难题。

Under the system that has held sway for three decades, member countries of the World Trade Organization set tariffs for every type of good, extending the same basic rate to all members. They have also negotiated treaties — with other countries, and via regional trading blocs — that have further eased tariffs.

在这个过去30年占据主导地位的体系下，世界贸易组织的成员国为每一种商品设定了关税，对所有成员实行相同的基本税率。它们还与其他国家或者通过区域贸易团体达成条约，进一步降低了关税。

Mr. Trump has long described the United States as a victim of this structure, citing trade deficits with China, Mexico and Germany. In announcing the advent of reciprocal tariffs on Thursday, he served notice that he claims authority to renegotiate the terms to his liking, absent respect for existing trade agreements.

长期以来，特朗普以美国对中国、墨西哥和德国的贸易逆差为由将美国描述为该体制的受害者。他在周四宣布对等关税的到来，明确表示自己有权按照自己的喜好重新谈判，毫不尊重现有的贸易协定。

上周四，印度总理莫迪和特朗普在白宫。同一天，特朗普签署命令，授意手下部门研究如何推进对等关税。

It seemed no coincidence that Mr. Trump made his announcement on the day that India’s prime minister, Narendra Modi, visited the White House. The United States runs a substantial trade deficit with India, with the value of its imported goods outweighing its exports last year by $45 billion.

特朗普在印度总理莫迪访问白宫的当天宣布这一消息，似乎并非巧合。美国对印度存在巨额贸易逆差，去年进口比出口多出450亿美元。

Those imports include plastics and chemical products that incur tariffs of less than 6 percent when shipped to the United States, according to data compiled by the World Bank. When similar categories of American goods are exported to India, they confront tariffs ranging from 10 to 30 percent.

根据世界银行汇编的数据，从印度进口的商品包括运往美国时关税不到6%的塑料和化学品。当同类美国商品出口到印度时，它们面临的是10%到30%不等的关税。

If the Trump administration were to lift American levies to equal levels, that would force American factories to pay more for chemicals and plastics.

如果特朗普政府将美国的关税提高到同等水平，那将迫使美国工厂为化学品和塑料支付更多费用。

The same pattern holds across a broad sweep of consumer and industrial products — footwear from Vietnam, machinery and agriculture from Brazil, textiles and rubber from Indonesia.

同样的模式也适用于众多消费品和工业产品，包括来自越南的鞋类、来自巴西的机械和农业产品、来自印尼的纺织品和橡胶。

A leading electronics industry trade association, IPC, on Thursday warned that increased trade protectionism would damage the American economy.

领先的电子行业贸易协会——国际电子工业联接协会周四警告，贸易保护主义的抬头将损害美国经济。

“New tariffs will raise manufacturing costs, disrupt supply chains, and drive production offshore, further weakening America’s electronics industrial base,” the association’s president, John W. Mitchell, said in a statement.

该协会主席约翰·米切尔在声明中表示，“新关税将提高制造成本，扰乱供应链，并将生产推向海外，进一步削弱美国的电子工业基础。”

Some experts see in Mr. Trump’s approach a potential negotiating tactic aimed at forcing trading partners to lower their own tariffs, rather than a prelude to the United States lifting its own. If that proves true, the process of calculating new tariff rates might actually lower prices.

一些专家认为，特朗普的做法是一种潜在的谈判策略，旨在迫使贸易伙伴降低自己的关税，而不是美国提高关税的前奏。如果事实证明这是真的，那么计算新关税税率的过程实际上可能会降低价格。

上海洋山港，摄于本月。在特朗普的第一个任期，当他开始对来自中国的进口商品加征关税后，向美国市场销售的公司将部分生产转移出了中国。

“There are a lot of ways this can go very badly for us,” said Christine McDaniel, a former Treasury official under President George W. Bush and now a senior research fellow at the Mercatus Center at George Mason University in Virginia. “But if he can get other countries to open up their markets, there is a narrow path where this could end up promoting trade,” she said.

“这对我们来说可能会带来很糟糕的结果，”乔治·W·布什政府的财政部官员、现任弗吉尼亚州乔治梅森大学莫卡特斯中心高级研究员的克里斯汀·麦克丹尼尔表示，“但如果他能让其他国家开放市场，就会有一条狭窄的通道，最终可能促进贸易。”

Still others warn that any process of negotiation could be guided less by national objectives than the interests of Mr. Trump’s allies. Tesla, the electric vehicle company run by the administration loyalist Elon Musk, could benefit from exemptions to increased tariffs on key components.

然而，也有人警告，这种谈判更多是受特朗普盟友的利益左右，而不是为了国家利益。由特朗普政府的忠实支持者埃隆·马斯克经营的电动汽车公司特斯拉可能会受益于关键零部件的增税豁免。

The tumult is leaving companies that operate in the United States having to guess how events will transpire as they weigh the costs of importing parts or finished goods. Business, as the cliché goes, craves nothing more than certainty. That commodity is getting more scarce.

这场混乱让在美国运营的公司在权衡进口零部件或成品的成本时，不得不猜测事态将如何发展。正如俗话所说，商业最需要的就是确定性。而确定性是一件越来越稀缺的商品。

Ever since Mr. Trump’s first term, when he put tariffs on Chinese imports — a policy that President Joseph R. Biden Jr. extended — companies that sell into the American market have shifted some production out of China.

自从特朗普在第一个任期对中国进口商品征收关税以来（拜登总统延续了这项政策），向美国市场销售产品的公司已经将部分生产转移到中国以外。

Surging prices to move cargo by container ship have prompted companies to close the distance between their factories and their American customers, a trend known as nearshoring.

集装箱船运价的飙升促使企业将工厂放在距离美国市场更近的地方，这一趋势被称为近岸外包。

Walmart, a retail empire ruled by the pursuit of low prices, has moved orders from Chinese plants to India and Mexico. Columbia Sportswear has scouted factory sites in Central America. MedSource Labs, a medical device manufacturer, has moved orders from factories in China to a new plant in Colombia.

以追求低价著称的零售帝国沃尔玛已将订单从中国工厂转移到印度和墨西哥。户外品牌哥伦比亚已在中美洲物色厂址。医疗设备制造商MedSource Labs已将订单从中国工厂转移到哥伦比亚的一家新工厂。

Mr. Trump has challenged the merits of such strategies by threatening 25 percent tariffs on imports from Mexico, Canada and Colombia, before quickly delaying or setting aside such plans. He has imposed across-the-board levies on steel and aluminum. He has delivered 10 percent tariffs on Chinese imports. Where he may turn next is the subject of a potentially expensive parlor game playing out in corporate board rooms.

特朗普不认为这些是有益的策略，他威胁要对从墨西哥、加拿大和哥伦比亚进口的商品征收25%的关税，但随后又迅速推迟或搁置了该计划。他对钢铁和铝征收全面关税。他对来自中国的进口商品加征10%的关税。企业的管理层将对他下一步的举动做出代价高昂的猜测。

一些专家警告，贸易谈判更多是受特朗普盟友（如埃隆·马斯克）的利益左右，而非国家利益。

Some surmise that the uncertainty stemming from these moves is precisely the point. Mr. Trump has long asserted that his ultimate goal is to force businesses to set up factories in the United States — the only reliable way to avoid U.S. tariffs. The more countries he menaces, the greater the risks for any company that invests in a plant somewhere else.

一些人推测，这些举措带来的不确定性正是目的所在。特朗普长期以来一直坚称，他的最终目标是迫使企业在美国设立工厂——这是避免美国关税的唯一可靠方法。他威胁的国家越多，在其他地方投资建厂的企业面临的风险就越大。

The trouble is that even businesses with factories in the United States depend on parts and raw materials from around the world. More than one-fourth of American imports represent parts, components and raw materials. Making these goods more expensive damages the competitiveness of domestic companies, imperiling American jobs.

问题是，即使在美国设厂的企业也要依赖来自世界各地的零部件和原材料。超过四分之一的美国进口商品是零部件、组件和原材料。提高这些商品的价格，会损害国内企业的竞争力，危及美国的工作岗位。

Last week, Ford Motor warned that tariffs on Mexico and Canada would wreak havoc with its supply chains.

上周，福特汽车警告，对墨西哥和加拿大的关税将对其供应链造成严重破坏。

“A 25 percent tariff across the Mexico and Canadian border will blow a hole in the U.S. industry that we have never seen,” the company’s chief executive, Jim Farley, said.

“对来自墨西哥和加拿大的商品加征25%的关税，将给美国工业带来前所未有的冲击，”该公司首席执行官吉姆·法利说。

For now, the business world is again struggling to divine which of Mr. Trump’s pronouncements are merely a gambit, and which portend real changes.

目前，商界又在努力推测特朗普的哪些声明只是一个策略，哪些预示着真正的变化。

On spreadsheets maintained by multinational companies, the applicable tariff rates for every country on earth suddenly seem subject to reworking.

在跨国公司的电子表格上，世界上每个国家的适用关税税率似乎突然之间需要重新调整了。

Or not.

但也不一定。

“We take Trump seriously, but not necessarily literally,” said Mr. Murphy, the trade lawyer. “He talks in broad strokes, but we have to watch what actually emerges.”

“我们认真对待特朗普，但并不总是完全按照他所说的字面意思去理解，”贸易律师墨菲说。“他说得很笼统，但我们必须观察实际情况是怎么回事。”