Was?
Maybe I'm living in some kind of alternate reality...
Mind expanding on which country or group thereof comes even close to having the same levels of economic activity, military might and diplomatic influence as the US?
China? Economic, hardly: it's getting there, but it's entirely dependent on the US consuming its output. Military: they're outgunned 6:1 by the US alone in terms of spending. Diplomatic: not the slightest bit, except on its immediate neighbors (and in Africa, to an extent, if you count showering local strong men with cash as influence).