Do you seriously contend that USA is wealthy solely because it is a capitalist economy? The current global hegemony of the US is surely due to many factors - not solely the nature of its economy. Its distance from Europe and ability to avoid entanglement in the wars that eroded European wealth and power, the vast largely undeveloped landmass and resources of the US, its fortunate position geographically all surely have played a major role in its current dominance. But USA is not a purely capitalist free market economy- any assertion that it is is easily refuted. The degree of cronyism in US politics and business today is obvious to any impartial observer, as is the importance of US military power. The USSR was never blessed with the geographic and historical advantages of the US and Japan was since WW2 effectively a military and monetary tribute state to the US- entirely reliant upon the US for protection and strongly influenced by US demands in terms of economic management. USA 'won' WW2 by staying out of it as long as possible and then once drawn into the conflict by a massive mobilisation directed by the government. Prior to WW2 the US had implemented substantial centrally directed economic reforms as had most western nations, adopting a mixed economy under Keynesian economic principles where the government drove major programs of economic development and stimulus. WW2 only increased the level of government involvement in the economy. China is qualitatively different- its economy today is a mixed one- with central government directing capital flows and overall strategy, mush as the US and western nations did until the neoliberal 'reforms' of the 1980s. Since those neoliberal reforms it can be said that capital allocation has shifted substantially from public driven initiative to private bankers. The building and maintenance of infrastructure in the US and west more generally has declined substantially and the US economy has become hugely dependent upon financialisation often involving debt leveraged speculation in non productive assets at the expense of infrastructure and productive assets. Chinas development is one based on mechcanical engineering- the construction of infrastructure and productive capacity, refining and manufacturing of raw materials and manufactured goods. The USA today has lost the physical manufacturing capacity required to sustain a military conflict or even a trade surplus. The USA today is a highly financialised highly debt burdened econoy with weak and declining infrastructure and massive inequality and political divisions. China is said to have a demographic problem but China is hugely in advance of the US in terms of robotics and the US also has an aging population and a significant lack of savings. China is raising the age of retirement for women from 50/55- to 55/60 and men from 55-60. The US does not have the same room to move. There has never been a successful empire without the careful and strategic involvement of government in directing capital and military capacity to build and sustain that empire. The contest between China and the US is real and not something to be easily dismissed with simplistic analysis- I would not like to have to pick the winner as the outcome is certainly not one that can be credibly called at this point. One thing is clear- the trends are mostly in Chinas favour at present. US decline is apparent across so many metrics while Chinas rise is equally clear across most metrics. It is folly to claim to know which side will triumph at this stage.