Taxation reduces the money supply. Government spending increases the money supply.

In particular, the central bank, charged with controlling inflation, cannot use taxation to reduce the money supply, because banks do not get to set tax policy. That leaves raising interest rates as its only policy tool.

As the political arm of the government chooses to run deficits in excess of growth plus inflation, then (a) that causes more inflation, and (b) the central bank raises rates, increasing the cost of government borrowing, causing bigger deficits.

This escalates as a result of the central bank trying to control the effects of high government spending by applying a mis-matched policy tool (interest rates) in place of the politicians who have abdicated their responsibility to use a matched policy tool (taxation).

If the central bank does not raise rates, of course, things go even more badly.