I think things will have to slide much much more than they already have for the world to write off the US as you suggest. Bush didn't do *that* much damage...
Let's just say it won't be a matter of the world writing off the US so much, but rather that the US economy is far too large for any one country or three to pull out of the mire. Even China, the world's second largest economy, would not be able to salvage it. The current Chinese loans are but a drop in the ocean compared to what is needed, and with the majority of Europe, Britain, etc, still struggling to recover from the last financial meltdown [and keep Greece afloat], dollars for economic aid are sparse.
Now talking about the present (and recent past) you can make this argument more strongly, but the advantages China is leveraging to gain this 'astuteness' are not exactly self perpetuating either. China needs external markets, if the US goes belly up, who are they selling to? Europe? Not likely, the EU is going to be (already is) having their own issues if the US fails. Middle East? Please, that's a drop in the bucket as a market goes. Aussies? Again, consumption is what drives the current Chinese model, you aren't making up that consumption in the rest of the world if the US flops. Thus, China can't afford to shut off the US, or hasten it's economic demise, unless China is planning do change it's own model.
Yes, China needs external markets if it is to continue on its path of manufacturing and economic growth, but if the market simply isn't there, as in US consumers are flat broke and aren't buying, then it will be forced to adjust its projections accordingly and produce less. And why won't the US economy bounce back like before? One: too many manufacturing jobs were sent offshore and now Chinese workers are performing the jobs US workers once did. Two: the US based a large part of its economy on its massive war machine and the production of arms, and both have gone into decline as the world begins to wise up and not go to war. Sure there will be despots and trouble makers rise up to upset the balance of things, but it won't be enough to fuel the US war economy.
US owned assets? You mean US government owned assets? How is China going to seize Microsofts assets? It's not the same thing.
As was mentioned above, many US manufacturers based their operations in China to exploit cheap labour, thus making the Chinese partners. Okay, so when their US counterparts cannot meet their financial obligations, etc, the Chinese will be entitled to take over the insolvent part of the company in order to protect its own investment. It's simple economics, really... the financially stronger partner will succeed over the weaker one. Now Microsoft mightn't be going guts up right now, and its assets in China may be safe for the time being, but the economic slide has not yet completed and its future as yet is undetermined. Should Microsoft fail to sell its Windows 8 to a shrinking market [who buys an OS (and/or Office) in difficult times], its fortunes could see a reversal for the first time in history and even the once solid MS finds itself the target of a hostile offshore takeover.
Some will be rubbing their hands with glee and saying that the pigeons have come home to roost, but me, well I'm not happy because Australia goes guts up when the US does. Too many Australian businesses were taken over by US concerns, and we simply do not have the resources any more to refinance, rebuild those businesses under new Australian ownership. Many food production factories will simply close, thus escalating unemployment and our dependence on imports. No, it is not a good thing, but the insatiable greed of US and Australian corporations {don't get me started on our effing bankers] has brought us to this. Let's face it, we are confronted with a new world order, economically speaking, and we'd better get darned used to it or be left a wanting.
