Yet from the 1950s through to the 1970s, debt-servicing dynamics were kept within manageable bounds. The rapid growth in economic output in the long post-war boom, which was aided by demographics and productivity performance, was a major help.
But also contributing was a combination of central banks holding down long-term interest rates at government direction, and banks and other entities being forced to hold government debt. And of course, at the end of that boom, a period of unanticipated high inflation played a role in lowering debt to GDP ratios.