First, What Is Sovereign Debt?
Think of sovereign debt like a country’s credit card or mortgage. When a government spends more money than it collects in taxes—running what’s called a budget deficit—it needs to borrow to cover the difference. It does this by issuing bonds, which are
essentially IOUs that investors, other countries, and even its own citizens can buy. In exchange, the government promises to pay back the loan with interest over a set period. This accumulated borrowing is known as sovereign or public debt. For years, this was a relatively manageable process, especially as global debt levels climbed to new heights following the 2008 financial crisis and the COVID-19 pandemic.
The Debt Mountain Gets Higher
Global public debt was already elevated before 2020, but the pandemic sent it soaring. Governments worldwide unleashed trillions of dollars in stimulus to support struggling households and businesses, funding these measures largely through new borrowing. By 2025, global public debt had risen to an eye-watering $111 trillion. This massive increase in the supply of government bonds would, under normal circumstances, force governments to offer higher interest rates to attract buyers. But for more than a decade, something else was happening that kept borrowing costs artificially low.
The End of an Era of 'Cheap Money'
For years after the 2008 financial crisis, central banks like the U.S. Federal Reserve and the European Central Bank kept their main interest rates near zero. This was done to encourage economic growth, and it created an environment of 'cheap money'. Governments could borrow vast sums at incredibly low costs. That era is now decisively over. Facing a surge in inflation, partly driven by post-pandemic supply chain issues and rising energy costs, central banks have aggressively raised interest rates. This makes borrowing more expensive for everyone, including governments. When old, low-interest debt matures, it must be refinanced by issuing new bonds at today’s much higher rates, causing interest payments to balloon.
A Vicious Cycle of Spending
This creates a dangerous feedback loop. As interest payments rise, they consume an ever-larger share of a government's budget. For example, in the United States, interest payments on the national debt have become one of the largest government expenditures, costing nearly a trillion dollars in fiscal year 2025. This is money that cannot be spent on other priorities. To cover these higher interest costs, a government might need to borrow even more, which, in a high-rate environment, just adds to the future interest burden. The International Monetary Fund (IMF) has warned that high debt makes government finances much more sensitive to interest rate hikes.
The Real-World Consequences
This isn't just an abstract problem for accountants in a finance ministry. When a government has to spend more of its revenue just to service its debt, it has less money available for everything else. This is called 'crowding out'. It can mean less funding for building schools, maintaining roads, supporting healthcare systems, or investing in new technology. The alternative is raising taxes on citizens and businesses to cover the shortfall. Furthermore, when governments borrow heavily, they compete with the private sector for available capital, driving up interest rates for mortgages, car loans, and business investments, slowing down the entire economy.
