TVC:US10Y   US Government Bonds 10 YR Yield
The Fed started raising the fed funds rate beginning in December 2015 but lowered it again in 2019 and 2020.
There are ongoing pressures to keep yields low. Economic uncertainty in the European Union, for example, can keep investors buying traditionally safe U.S. Treasuries. Foreign investors, China, Japan, and oil-producing countries need U.S. dollars to keep their economies functioning. The best way to collect dollars is by purchasing Treasury products.
In the long-term, these factors can put upward pressure on Treasury yields:
The largest foreign holder of U.S. Treasuries is Japan followed by China. China has threatened to purchase fewer Treasuries, even at higher interest rates. If this happens, it will indicate a loss of confidence in the strength of the U.S. economy. It would drive down the value of the dollar in the end.
One way the United States can reduce its debt is by letting the value of the dollar decline. When foreign governments demand repayment of the face value of the bonds, it will be worth less in their own currency if the dollar's value is lower.
The factors that motivated China, Japan, and oil-producing countries to buy Treasury bonds are changing. As their economies become stronger, they are using their current account surpluses to invest in their own country's infrastructure. They are not as reliant upon the safety of U.S. Treasuries and are starting to diversify away.