Lingua franca
Back in the day, the US made things. Lots of primary, secondary and tertiary production. Food, cars, tools, industrial machinery and so forth. Equipped with everything it needed to go from ore-in-ground to product-on-shelf, and providing all the knowhow and labour, and even a large market to consume the produce, economies of scale translated more or less directly into profit.
It was not strictly necessary to sell at a profit. This placed the US very nicely to destroy any competitors by selling at a loss for as long as it took. Once competition had been eliminated, prices were raised and losses recovered. The US was hardly the first nation to behave like this, but it was probably the biggest and most effective.
But the US no longer exports much of anything, except possibly guns and political trouble. This is a bit of a worry for us here in Australia: lingua franca literally means language of money, and US was the economic mainstay of the English speaking world. The British Empire is long gone, the American star wanes and trade winds, I fear, all blow east.
This may be mitigated by the face that alphabetic languages are far better suited to use with computers, and by the fact that English is better suited to rapid technological change.