NOTE To Clinton: The U.S. has been the world's leading military power since 1864, when the combined Northern and Southern Armies boasted millions of men, gatling machine guns, electric mines, repeating rifles, mass production, aerial balloons, speed-of-light communications via electric telegraph, while Northern and Southern Navies boasted steam-powered iron-clads with revolving turrents and combat submarines - all at a time when state-of-the-art warfare in Europe consisted of infantry with unrifled muzzle-loaders and woodern sailing ships for navies.
Though European history texts deny it to this day, the U.S. military has been the most advanced and most powerful for the last 140 years.
The American economy has been the world's most advanced and largest financial empire since at least 1890, more than a Century ago.
America is more than 40 years ahead of China, India, Japan, and Europe in orbiting a man around the Earth, and more than 3 decades ahead of the rest of the combined world in placing a man on the Moon, so the concept that some other nation "must" surpass us in the next 50 years is absurd. Sure, it could happen, but it's not very likely.
For all of those reasons and more, Clinton is wrong. In fact, not only is he wrong, but he's uninformed and misguided. His left-leaning politics are pretty questionable, too (so far as patriotism is concerned).