美元霸主地位岌岌可危？

At the outbreak of the first world war, investors sold dollars and bought sterling. It ought to have been the reverse, since Britain had declared war and the US was standing apart. But crowds rush to safety in a crisis — and sterling was then the reserve currency. Little did they guess that sterling would be undone by war debt.

第一次世界大战爆发时，投资者卖出美元，买入英镑。按理他们应该进行相反的操作，因为英国已经宣战了，而美国仍处于中立。但在危机中，人群涌向安全港——而英镑当时是储备货币。没人想到英镑将因战争债务而崩溃。

Markets reacted the same way after the 2008 Lehman Brothers collapse. Although the crisis began on Wall Street, the dollar rose; America was rewarded for its sins. But profligacy cannot go on indefinitely. By his actions, Donald Trump is bringing forward the dollar’s reckoning.

2008年雷曼兄弟(Lehman Brothers)倒闭后，市场的反应也是一样。虽然危机始于华尔街，但美元却上涨了；美国因其罪恶而得到嘉奖。但挥霍不可能永无止境。唐纳德`特朗普正以实际行动提前了美元的清算日。

The US president’s most tangible impact is on public debt. If Mr Trump’s tax cuts do not expire, as they are meant to within a decade, US sovereign debt will rise from 77 per cent of gross domestic product today to 105 per cent by the end of 2028. That would roughly equal its highest level in history, which was during the second world war. By comparison, Italy’s debt is 131 per cent of GDP.

这位美国总统最实实在在的影响是在公共债务上。倘若特朗普的减税政策不按照计划在10年后失效，美国主权债务与国内生产总值(GDP)之比将从目前的77%升至2028年底的105%。这将大致相当于二战期间的历史最高水平。相比之下，意大利的债务与GDP之比为131%。

Under current law, which is what the Congressional Budget Office must assume, US debt would reach 96 per cent of GDP in 10 years. In practice the only metric that counts is Washington politics, which says that temporary tax cuts are permanent.

根据现行法律——美国国会预算办公室(Congressional Budget Office)必须据此作出假设——美国债务将在10年后达到GDP的96%。在实践中，唯一重要的衡量标准是华盛顿的政治，这意味着“临时”减税政策将是永久的。

At what point does America’s broken politics risk the dollar’s supremacy? All things being equal, today’s mess could carry on for another decade or two. It has been building for about as long. Unlike Italy, the US has its own currency, which means it can keep printing dollars at will. Japan, which has central government debt of almost 200 per cent of GDP, shows that red ink need not trigger a crisis. But the global reserve currency must follow a higher standard than Japan’s does.

美国支离破碎的政治在什么时候会危及美元的霸主地位？在其他所有条件都相同的情况下，现在的烂摊子可能还能撑10年到20年。这种局面已经发酵了差不多同样长时间。与意大利不同，美国有自己的货币，这意味着它可以随意印制美元。

We cannot know which path is likelier. We do know that Mr Trump is allergic to smooth transitions.

我们不知道美国更有可能走上那条路。只知道特朗普对平稳过渡“过敏”。