1) By the central banks buying up treasuries. Look out how manyUS treasuries the FED has added to its balance sheet in the past year. If you have an entity that does not play by market rules eating up the market demand for products it will suppress rates. If the Fed was not buying the treasuries there would not be as much demand and the rates would need to go up in order to interest enough lenders.
The only reason a lot of the banks who hold treasuries or certain bonds are willing to do so is because they are positioned long and borrowing short. IE no one smart buys a bond that pays 2% in any interest enviroment. But you do if you are buying that asset with someone else's money at a lower rate. Utilizing this cheap money the FED has created investors are buying long term debt at low interest rates financed with short-term loans at artificially low rates that roll over constantly. You can make a nice profit on something that only pays 2 % if you buy it with a loan you need to pay 1% on and are leverage 30 to 1. The problem is as soon as the short term loan rate of interest goes up or the asset price collapse and your lender will not allow you to roll over the loan you are well underwater since you are so heavily leveraged. This is what happened in 08 and why these investment firms went from solvent to massively indebt literally overnight.
2) Duh, how many bonds did the FED have on its balance sheet when Volcker inverted the yield curve. Pretty sure the FED's balance sheet was not at $8 trillion and the US government didn't have $8 trillion in short-term debt.
In 1970 the FED balance sheet was about 8% of GDP, by the time Volcker had defeated stagflation it was at around 6% of GDP. The FED balance sheet is at almost 40% of GDP and expanding. Instead of reducing the supply of money it is being expanded when inflation already exists. Our current monetary policy goes against every basic economic principle and historical lesson of what to do to stop inflation. There is a reason the FED stopped its weekly publishing M1 at the end of March after doing so for decades. They realize there is a crisis on their hands and are trying to delay the day of reckoning. Powell is hoping at this point to end his term before the crisis really strikes then he can pull a Bernanke and go on a book tour about how he saved the US economy from the COVID crisis and dump the problem on his successor.