Because we're America and that's why we're always great. It's not because the WWII generation kicked ass and took names. It's not because our industrialists created pretty much every invention out there that is carrying the rest of the world into the first world with 100 year old technology. It has nothing to do with those evil rich white men back in the 1700's who created that worthless constitution of the United States or that dumbass "Bill of Rights."
No, it's because we support America and wave flags and cheer really loud and we've always been great. That's why we'll continue to be great! Because our greatness is great and we're America! Cheery happy soccermommy-Apple-Bee's-and-Blockbuster-America!