In The Arrogant Empire, Fareed Zakaria explains that Americans felt vulnerable after 9-11, but “the rest of the world saw something quite different”:
Yet after 9-11, the rest of the world saw something quite different. They saw a country that was hit by terrorism, as some of them had been, but that was able to respond on a scale that was almost unimaginable. Suddenly terrorism was the world’s chief priority, and every country had to reorient its foreign policy accordingly. Pakistan had actively supported the Taliban for years; within months it became that regime’s sworn enemy. Washington announced that it would increase its defense budget by almost $50 billion, a sum greater than the total annual defense budget of Britain or Germany. A few months later it toppled a regime 6,000 miles away — almost entirely from the air — in Afghanistan, a country where the British and Soviet empires were bogged down at the peak of their power.
And here’s some evidence that America has become the world power:
It is now clear that the current era can really have only one name, the unipolar world — an age with only one global power. America’s position today is unprecedented. A hundred years ago, Britain was a superpower, ruling a quarter of the globe’s population. But it was still only the second or third richest country in the world and one among many strong military powers. The crucial measure of military might in the early 20th century was naval power, and Britain ruled the waves with a fleet as large as the next two navies put together. By contrast, the United States will spend as much next year on defense as the rest of the world put together (yes, all 191 countries). And it will do so devoting 4 percent of its GDP, a low level by postwar standards.