Fortunately, taking on more debt for spending/consumption and to service older debt has not been a problem. Over the past twenty years there have been willing lenders (savers) to fund this scheme, even as their reward, measured in yield, steadily declined.
Unfortunately, two of the largest buyers/holders of U.S. Treasury debt (China and the Federal Reserve) are no longer pulling their weight. More concerning, this is occurring as the amount of Treasury debt required to fund government spending is growing rapidly. The consequences of this drastic change in the supply and demand picture for U.S. Treasury debt are largely being ignored.
Foreign Bond Holders
In our article, Triffin Warned Us, we provided a bit of history on the Bretton Woods Agreement. This pact from 1944 essentially deemed the U.S. dollar the world's reserve currency. As a result of the agreement, foreign nations rely heavily on U.S. dollars for all types of international trade. For instance, if Uruguay sells widgets to Australia, Australia will most likely pay Uruguay in U.S. dollars. Because of the reliance on dollars for trade, Uruguay, Australia and almost every other nation holds reserves of dollars.