Hi doma,
Maybe you are thinking about quantitative easing.
The context in which QE is viable is when the currency is in a deflationary phase, as it has been and continues to be. While this continues, it makes sense to issue new money/ buy treasuries.
If US treasuries continue to run low interest rates, this tells you the market still has confidence in the value of US debt. This is the situation we are seeing now. People still want to hold instruments which will maintain their value. They believe Treasuries represent a safe store of value. They bid up the price etc.
If the market begins to see better value elsewhere, then treasury values will begin to fall and treasury interest rates will begin to rise; at some point, the whole federal reserve monetary process will go into reverse. You'll see quantitative tightening (ie normal monetary responses), to combat inflation. The Fed will also reverse the debt transaction with the US treasury, which can be achieved much the same way as it was implemented: stroke of a pen.
When the US owes money to itself, this is a bit different from when it owes the money to foreign governments.
In a year, you'll give yourself another year, as all the other prophets of doom do. ;-) But the post-crash inflationistas have mostly discovered their economics fails in a depression type of environment in which the central bank remains a credible force.
The point? Monetary policy is contextual. The opposing forces in play probably limit the amount of QE which can be undertaken all at once. But the Fed can do a whole bunch of treasury purchasing without creating inflation in a depressed economy.
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