President Trump’s promise to impose 25 percent tariffs on Monday on all U.S. imports of steel and aluminum would primarily target American allies, but at their heart they strike at his longtime nemesis: China.

特朗普总统承诺本周一开始对所有进口到美国的钢和铝征收25%的关税，这一举措主要针对美国的盟友，但其核心直指特朗普长期的对手：中国。

The top five suppliers of steel to the American market in January were Canada, followed by Brazil, Mexico, South Korea and Germany. Canada has also led in aluminum exports to the United States, while the United Arab Emirates, Russia and China are far behind.

今年1月美国市场上的前五大钢材供应国依次是加拿大、巴西、墨西哥、韩国和德国。加拿大向美国出口的铝材也居美国进口总量的榜首，而阿联酋、俄罗斯、中国向美国出口的铝材远少于加拿大。

China does not export a lot of steel or aluminum directly to the United States. A succession of presidents and Commerce Department rulings have already imposed many tariffs on steel from China. Tariffs have also gone up lately on Chinese aluminum. Just last September, President Joseph R. Biden raised existing tariffs on many Chinese steel and aluminum products by up to 25 percent.

中国直接向美国出口的钢材或铝材并不多。多届美国总统和商务部的裁决已对来自中国的钢材加征了不少关税。对中国铝材征收的关税最近也有所上调。仅在去年9月，拜登总统就将对中国的许多钢和铝产品的现有关税上调了25%。

But China dominates the global steel and aluminum industry. Its vast, modern mills make as much or more of both metals each year as the rest of the world combined. Most of it is used within China’s borders, to build everything from high-rises and ships to washing machines and cars.

但中国主导着全球的钢、铝行业。中国庞大的现代化冶炼厂每年生产的这两种金属材料与世界其他国家生产的总和相当，甚至更多。中国生产的钢材大部分在国内使用，用于建设从高层建筑和轮船、到洗衣机和汽车等各种东西上。

Yet lately, China’s steel and aluminum exports are on the rise because its economy is struggling, sapping domestic demand. Many of these low-cost exports have gone to American allies like Canada and Mexico, which in turn export significant shares of their own more expensive output to the United States. Other Chinese metal exports have gone to developing countries like Vietnam, which now buys enormous quantities of semi-processed steel from China, finishes it and then re-exports it as Vietnamese steel to buyers around the globe.

但中国的钢材和铝材出口最近出现上升，因为该国的经济面临困难，使得国内需求下降。许多这些低价出口产品流向了美国的盟友，比如加拿大和墨西哥，而这些国家随后又将本国相当一部分造价更高的产品出口到美国。中国的其他钢材和铝材出口销往越南等发展中国家，越南目前从中国购买大量的半成品钢，在国内进行加工后，将其作为越南钢再次出口到全球各地。

China’s rising exports have upset producers and labor unions in the United States.

中国钢材和铝材出口不断增长，已经令美国的生产商和工会感到不安。

“China’s overcapacity is swamping world markets and severely injuring U.S. producers and workers,” said Michael Wessel, the longtime trade adviser to the United Steelworkers of America.

“中国的产能过剩正在给全球市场造成冲击，严重损害了美国的生产商和工人的利益，”美国钢铁工人联合会的长期贸易顾问迈克尔·韦塞尔说。

China’s foreign ministry had little to say specifically about the planned steel and aluminum tariffs at its daily briefing on Monday. “Let me stress that protectionism leads nowhere. Trade and tariff wars have no winners,” said Guo Jiakun, a ministry spokesman.

中国外交部在周一的例行记者会上对美国打算提高钢材和铝材关税的问题几乎没有任何具体评论。“我要强调的是，搞保护主义没有出路，贸易战、关税战没有赢家，”外交部发言人郭嘉昆说。

The planned tariffs come a week after President Trump imposed a 10 percent tariff on all imports from China. Last week, China announced that it would impose retaliatory tariffs, set to take effect on Monday, on liquefied natural gas, coal, farm machinery and other products from the United States.

在征收这些新关税的一周前，特朗普已对所有来自中国的进口产品加征了10%关税。中国上周已宣布反制措施，从本周一起对来自美国的液化天然气、煤炭、农业机械，以及其他产品征收报复性关税。

China’s steel glut arose from an extraordinary boom in steel mill construction that started during the early 1990s and lasted for about 15 years, said Nick Tolerico, a senior steel trade official throughout the Reagan administration who then became the president of U.S. operations for ThyssenKrupp Steel of Germany. He is now a consultant advising investment firms and companies that buy a lot of steel.

中国的钢铁供应过剩，原因是中国从20世纪90年代初开始的炼钢厂建设热潮一直持续了约15年，尼克·托勒里科说，他曾在整个里根政府期间担任高级钢铁贸易官员，后来担任过德国蒂森克虏伯钢铁公司的美国业务总裁。他现在为投资公司和购买大量钢铁的公司提供咨询服务。

Not seen since the 1940s has any country commanded the world’s steel industry on China’s scale today. The United States made half the world’s steel then, but its share has fallen since then to less than 5 percent.

自20世纪40年代以来，还从来没有一个国家以当今中国的规模主导世界钢铁行业。虽然美国曾在20世纪40年代生产了全球一半的钢铁，但此后其份额已降到5%以下。

For years, China’s construction industry used immense quantities of steel. A building boom produced abundant housing for the country’s 1.4 billion people and enough empty apartments for another 300 million people.

多年来，中国的建筑业消耗了大量的钢材。这场建筑热潮除了为中国的14亿人口提供了充足的住房外，也制造了足够另外3亿人居住的空置公寓。

The overhang of empty apartments has now propelled a housing market crash and an abrupt stall in construction. Desperate to avoid shutting down, China’s mills have responded with a surge in steel exports to countries all over the world. They have accepted lower and lower prices for their steel over the last several years, triggering a global erosion in prices.

空置公寓的积压现在已导致了房地产市场崩溃，建筑业突然停滞。为避免关闭，中国的炼钢厂采取了向世界各国大量出口钢材的做法。它们在过去几年里接受了越来越低的价格，导致了全球性的价格下跌。

The falling prices have hurt the American steel industry, a politically powerful constituency in key electoral regions. The United Steelworkers of America is headquartered in Pittsburgh, at the core of the industry’s longtime base in Pennsylvania, which has proved central to recent presidential elections. U.S. Steel, an emblem of America’s formerly outsize role in steel production, is also in Pennsylvania.

钢价下跌已给美国的钢铁行业造成伤害，该行业在几个关键选区具有很大的政治影响力。美国钢铁工人联合会总部所在的匹兹堡位于该行业的长期大本营宾夕法尼亚州的核心地带，而宾夕法尼亚州在最近的总统大选中被证明起了重要作用。美国钢铁公司也在宾夕法尼亚州，该公司是美国曾在钢铁生产上起过重要作用的象征。

The steel trade backlash against China is not confined to the United States. Brazil, Canada, Indonesia and Turkey have all raised tariffs sharply in the past year on steel from China.

对中国钢材出口增加的反弹不仅来自美国。巴西、加拿大、印度尼西亚和土耳其在过去一年里都大幅提高了对中国钢材的关税。

During his first term, President Trump imposed supplemental 25 percent tariffs on steel and 10 percent tariffs on aluminum imports from all over the world. He then exempted big steel-producing countries like South Korea, Australia and Brazil from the tariffs in exchange for their imposing quotas for how many tons of steel they would ship each year to the United States. But he left the tariffs in place for China.

特朗普在第一次担任总统期间曾对来自世界各地的钢材进口征收了25%的附加关税，对来自世界各地的铝材进口征收了 10%的附加关税。后来，他免除了对韩国、澳大利亚、巴西等钢材生产大国的附加关税，作为交换，这些国家对它们每年向美国出口的钢材吨数进行了额度限制。但特朗普保留了对中国钢材的关税。

The trade protections helped the American steel industry, which over the past six years has increased its capacity by about one-fifth, building modern steel mills. Older, less-efficient mills have started to run at less than full production.

贸易保护主义曾为美国钢铁行业提供了帮助，美国钢铁行业在过去六年里将产能提高了约20%，建设了现代化的炼钢厂。较老、效率更低的炼钢厂已开始以低于满负荷生产的能力运行。

By the last week of January, steel mills in the United States were operating at 74.4 percent of capacity, according to the American Iron and Steel Institute, a Washington-based industry group.

据总部位于华盛顿的行业组织美国钢铁协会，截至今年1月的最后一周，美国炼钢厂的产能利用率为74.4%。