An interesting one. What does it take to rise? Generally rises occur from confidence - in strength, goal etc. Falls occur through loss of strength, internal weaknesses, corruption etc.
Most falls appear to have occurred when the people still believed in their own/country rectitude, but were not seeing below the surface.
One of the things that comes across to me, as an outsider, is that America/ns now seem to be more fearful, more insecure, and therefore more aggressively defensive than previously. I am not sure how this plays out in looking for a rise. A rise fuelled by fear implies aggression in one or more forms.
If we look at China, I see parallels. China fears the US in particular, other countries to a greater or lesser degree. This fear drives the development of the military. It also fears those within its borders. Dissent is 'discouraged' - and this seems to occur in the US as well. Media is both countries seems to follow the 'right' line - support for military, strength required against China/US - other 'enemies',
Will both countries rise in fear of the other? China is determined to topple the US economic leadership, it is already 2nd in military strength and devotes an enormous percentage of budget to increasing military strength. And this from a country that still vociferously sees itself as 'developing'. The US is certainly not cutting back on its military spending. Including non-DOD expenditures, defense spending was approximately 25–29% of budgeted expenditures and 38–44% of estimated tax revenues. That's a LOT of money headed into maintaining pole position.
The other question - what if they both fall? If China's housing bubble bursts then a world wide financial fallout will occur. Even the Chinese gov't has recognised that it HAS to continue with 8% or more growth to maintain social stability. Any drop below that could be ... interesting.
To maintain that growth, China must have 15% of the world market - currently it has around 10%, Where does that additional 5% come from? Internally - yes and no. To increase exports prices need to be kept low - in turn meaning low wages. Low wages means no growth in the internal market. Will Europe be importing more? Not really, given its current financial status, and the US ? Also needs market share and the financial problems are still biting there. That leaves taking over markets from other developing countries.
Any further problems with the US financial status will again create international problems. And China will want to hedge against this. US markets are contracting, with European economic failures, and there are predictions of double dip recession. How many more stimulus packages can the US gov't find?