If public debt is large enough that the risk of default is a real possibility, the government may deem austerity measures necessary. Without intervention, with so much debt, lenders will charge a higher rate of return, making the raising of capital more difficult.
There are three primary types of measures:
1. Revenue generation via higher taxes
2. Cutting non-essential government functions with a concomitant rise in taxes
3. Lower taxes while lowering government spending

There are arguments against each. In the first, it is unclear higher tax percentages result in higher tax revenues. Humans and companies respond to increases in tax percentages dynamically and can offset the taxes in different ways leaving the government with no more money. Second, an efficient government is rarely spending enormous amounts of money on non-essential’ operations. Where this is not true one has to wonder why the government was so bloated anyway. Third, many people think lowering taxes allows wealthy people to get away with not paying a “fair share”. Lowering spending can have subsequent order effects. Decreased funding for police might be met with necessary increased spending on court-proceedings/prison-maintenance after a resultant rise in crime.