I've just finished Adam Fergusson's 1975 book on Weimar Germany, Austria and Hungarian HT. The parallels are alarming and the US is not at war to the extent of WWI and German's reparations, though current US military budget approaches Germany's debt to Versailles relative to GDP. However, as has been pointed out various times in this thread, higher aggregates will evaporate in our economy, which was not possible in the Axis economies. Paper money just kept piling up.

What we are seeing and I think will continue to see are larger and larger bubbles and busts. Investors will be scrambling from one volatile market to another. The dollar is strong, and the UST are selling like hot cakes, in my opinion because it's the only game in town. Europe is not credit worthy at any interest rate and Asia (and everyone for that matter) is depreciating their currencies to prop up exports. In this environment the US can get away with issuing more bonds while lowering its interest rates by buying them with new dollars. The inflationary risk of UST is stifled by the massive flight from the euro.

Catch me please if and where my logic is unsound.

The US has created a very risky but profitable scenario. They will continue to issue bonds, indeed they must as long as the budget is unbalanced, and can keep the rates low by buying many of them back with new M0, thus slowing down the appreciation of the dollar which will be applauded by the US export industry, workers, and politicians. I don't see what would pop this transparent ponzi bubble. As long as the USD appreciates against gold, money will continue to flood in to the US, interest rates for many foreign bonds will increase until default, which will pump UST even more.

What possible scenarios would decrease demand for UST and what would force the interest rate up?