Well, I think you did put your finger on part of the problem. This whole argument is US-centric. We are always talking about problems in America. The whole debate is about the USA. The value of the dollar. Housing prices in the States. Wal-Mart. Republicans.
It seems that from obesity to SUVs to easy credit, Americans lack the capacity to say, no. Why is that?
If you take statistics in aggregate you will see that savings rates are at historical lows and are actually negative, while personal debt levels are at highs. That disguises the fact that many homeowners do not have mortgages at all. I will have to hunt for the number, but I believe it is 45%? Maybe it is 35%? In any case, any meltdown will affect people in different backgrounds unevenly. The lower-middle class, the poor and those deep in personal debt the most. No one ever held a gun to their heads and told them consume today or else!
If the US consumes 70% of the world's savings than by definition the rest of the world is probably saving quite a bit of their income to GDP? So as we are having a US-concentric argument here, really this is a made in the USA problem. I am glad at least something is still made in the USA?

Just kidding.
However, just because Americans on average save less than they earn, this is a liquidity problem. They are cash poor. That does not mean that the total debt exceeds the value of all assets. At a 60% discount, like when Argentina defaulted on their debts, I would be a huge buyer of American assets - companies, intellectual property, patents, trademarks, banks, white collar workers, etc. At that price the international buyers would be lined-up around the block to buy America on the cheap. If you're going to mortgage your future, you better hope you can make the payments. That is not to suggest that America is not worth anything, anymore than a decade of recessions undermined the real networth of Japan or HK. The price of assets went down, but did not go away. They still have intrinsic value.
Peak Oil is not the biggest problem facing America today. Overweight adults and children, obesity and health related problems such as adult onset diabetes affects more Americans than a recession will. Why do you obsess about conspiracy theories and events that have only a small likelyhood of ever happening, while eating yourselves to death? Really, this is putting the cart before the horse. If you're going to worry about the future, make sure you have one
Japan was able to learn from the oil shocks of the 70's and now consumes less than two thirds the energy per unit of GDP as the G7 average. Why was not America also able to absorb these lessons? I see US politicians flying around the globe time and again asking other countries to voluntarily restrain themselves from producing and exporting to save American jobs. Why do not Americans buy American made goods? It would be a simple solution to your trade deficit and in turn support the US dollar so it does not collapse. If American products are more expensive then this would be an incentive to save. This would create less dependence on imported foreign capital.
Budget deficit and debt got you worried? Why not raise taxes and close tax loopholes. Eliminate the deficit and reduce the debt to GDP ratio. The solutions are easy, but the will is lacking. Instead you're obsessing on Roe vs. Wade for the umpteenth time and electing your politicians based on their views on gay marriage.
Instead of solving your problems and getting on with life you spend all your time ranting and raving that the market does not work, that capital markets are rigged, that finance is all smoke and mirrors and that economists have no idea what they are talking about. All I can say is grow up. Stop blaming all your problems on the rest of the world. Go elect Al Gore or John Kerry or Hillary Clinton if you think they can solve your problems, but they cannot and they will not.
Or as Benjamin Franklin said,
'Laziness travels so slowly that poverty soon overtakes him.'
The organized state is a wonderful invention whereby everyone can live at someone else's expense.