text: That's hard to predict.  America's economic strength, and the military strength that is a byproduct of it, come from having a established institutions - government, economic, and social - that allow people to pursue interests, and succeed or fail, then allow them to try again.  Most other countries in the world do not have the same depth of institutional strength in all these areas as the US, but as they develop them, China and India in the long term have the best chance of overtaking the US, though that may take at least 100 years.  Europe, should it ever truly develop into  something closer to the US in structure, and reform its institutions, could overtake the US more quickly if it made the effort, but the nations of western Europe would need to find more common ground with each other for that to happen, and the common ground is not going to be defined in Brussels.