US relies heavily on foreign nations to buy her T Bills. Japan debt is 200 percent of GDP, but her citizens buy 90 percent of the T Bills sold. The US has to print money to buy back 40 to 75 percent of the new T Bills offered. Japan demonstrated that gov can keep printing as long as her citizens are willing to buy most of the gov T Bills. This maybe one mechanism the US gov will cope with high deficits financed by dollar printing. Force all Americans to invest in T Bills. US did that after WW2 to pay off her war bonds. It worked. Low interest rates help people in debt to deleverage. IMHO the US banks probably have huge leveraged liabilities that are hidden from the public and badly need the low interest rates. IMHO the US gov will print unless the dollar is being dumped by overseas holders, or inflation is starting to reel its ugly head, and at that moment the US gov will begin financial repression by making US gov workers invest in T bills only in their TSP to protect them from the stock market. Or the gov will wait till the stock market crashes and offer older Americans to replace their entire portfolio plus make up the losses with US T bills with one stipulation, from that point on the worker will buy only T bills till the day he/she retires or tell the retiree to take his/her chances that the market will make up for all the losses.
Between financial repression, and new found revenues from fracking oil and gas, the US gov may stabilize its financial situation assuming no Black Swan event.
Over the last 6 years, the Fed has only bought about 17% of new debt issued.
Or the gov will wait till the stock market crashes and offer older Americans to replace their entire portfolio plus make up the losses with US T bills with one stipulation, from that point on the worker will buy only T bills till the day he/she retires or tell the retiree to take his/her chances that the market will make up for all the losses.