Why is the American economy strong?

Normally an article as illiterate and badly written as this [Found through Kiruba] wouldn’t pass through my first line of defence. It essentially accuses the US economy of living off the savings of the rest of the world.
Except that I have read a more sophisticated analysis (Link requires subscription) of how the American economy stays afloat inspite of a huge current account deficit and remain distinctly unconvinced.
The problem is this: Americans don’t save. They borrow a lot. They import much more than they export, (in Economese, this means that they have a large “current account deficit” ). So why is the American economy strong? The Economist article basically claims that it is because everyone else treats the dollar as the equivalent of a gold standard. All other countries are perfectly happy to sell their goods to Americans and keep the dollars that they get in return because they are confident that someone else (not necessarily the Fed) will buy the dollar at stable rates. Looks like a bubble to me.