Why does excessive debt ultimately result in deflation? Because debt fuels price increases on all manner of goods and assets above what a market could otherwise sustain. And, as any mean-reverting value, prices at some point have to revert to the trend mean, i.e. come down once they're no longer supported by debt and carry-trade speculation.

So to fight asset price deflation, however noble the intent, is akin to fighting stock market corrections. You can only do it by  increasing money supply, or velocity, or both. At some point, when the global appetite for risk is on the wane, the only remaining action is to run the printing presses, reflating the debt bubble while hoping that confidence in US dollar and our governement's IOUs doesn't go pop.

How long will the market accept zero yields on Treasuries for an ever-more-hollow promise of security? For now, it's a victory by default - by virtue of being less bad than the alternatives, and building on USD's standing as reserve currency since the end of WW II. Can it be sustained? For how long? How will we (the US) bear the debt burden going forward?

I'm afraid we'll be forced to find out soon enough.