在其建国250周年之际，美国依然是一个超级大国，尽管其相对主导地位已经有所削弱。在1820年，美国是一个仅有1000万人口的小国，经济规模只有大英帝国的十分之一。在1891年能源消耗超过英国并在1899年控制了广袤的肥沃土地后，其经济于1903年成为世界第一。到1945年，美国以仅占全球6%的人口控制了全球约三分之一的产出，并生产了全球50%的制造品。如今，它依然拥有32.4万亿美元的国内生产总值（比中国大55%），并且在全球十大最值钱的公司中占据八席。
然而，随着战后世界经济增长了19倍，美国的相对全球份额有所缩小。到2024年，其制造业产出比例降至15%，仅为中国份额的一半，美元在全球外汇储备中的份额也降至57%。虽然“中国冲击”在1999年至2011年间导致了240万个美国就业岗位的流失，但美国经济表现出了韧性，保持着每月400万个就业岗位的常规更替。在军事上，美国拥有无与伦比的硬实力，拥有11艘现役航空母舰，而中国仅有3艘；美国还为2027财年提出了1.5万亿美元的国防预算，比2026财年增加了44%。
在唐纳德·特朗普的领导下，美国政策正将资源移出传统的全球影响力支柱。通过美国国际开发署（USAID）提供的官方发展援助被削减至290亿美元，大约是之前水平的一半。联邦研究也面临限制，去年有超过7800项赠款被冻结或终止，使得中国的研发支出超过了美国。此外，严格的移民政策导致今年净移民人数接近于零，全球有意向的移民中仅有15%将美国列为首选目的地，低于2007至2009年间的24%。因此，六成美国人认为到2050年他们的国家在全球舞台上的重要性将会降低。
On its 250th anniversary, the United States remains a superpower, though its relative dominance has eroded. In 1820, America was a small nation of 10 million people with an economy one-tenth the size of the British Empire. After overtaking Britain in energy consumption in 1891 and controlling vast fertile lands by 1899, its economy became the world's largest in 1903. By 1945, with only 6% of the global population, America controlled one-third of global output and produced 50% of manufactured goods. Today, it still boasts a $32.4 trillion GDP, which is 55% larger than China's, and accounts for eight of the world's ten most valuable firms.
However, America's relative global share has shrunk as the post-war world economy grew nineteen-fold. Its manufacturing output fell to 15% by 2024, half of China's share, and the dollar's share of foreign-exchange reserves declined to 57%. While the "China shock" cost 2.4 million American jobs between 1999 and 2011, the economy showed resilience, maintaining a monthly churn of 4 million jobs. Militarily, America maintains unmatched hard power with 11 operational aircraft carriers compared to China's three, and has proposed a $1.5 trillion defense budget for the 2027 fiscal year, a 44% increase over 2026.
Under Donald Trump, US policy is shifting resources away from traditional pillars of global influence. Official development assistance via USAID was cut to $29 billion, roughly half its previous level. Federal research has faced constraints, with over 7,800 grants frozen or terminated last year, allowing China’s research spending to exceed America’s. Furthermore, strict immigration policies have led to near-zero net migration this year, with only 15% of prospective global migrants naming the US as their top destination, down from 24% in 2007-09. Consequently, six in ten Americans believe their country will become less globally important by 2050.
Source: America is mighty—but becoming less dominant
Subtitle: Ahead of its 250th birthday, an empirical look shows the world’s leading country no longer stands so far apart
Dateline: Jul 02, 2026 06:24 AM