Key Takeaways:
- US national debt held by the public has reached 100% of GDP
- The ratio approaches post-World War II highs last seen in 1946
- Rising debt-service costs exceed defense spending, limiting fiscal flexibility
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US national debt hits 100% of GDP, approaching post-WWII highs
US debt held by the public has reached 100% of gross domestic product, a level not seen since the aftermath of World War II.
US national debt held by the public has reached 100% of gross domestic product, crossing the 90% threshold that academic research flags as a danger zone for economic growth and raising questions about the trajectory of federal borrowing. The ratio now stands at levels last seen in 1946, when it peaked at 106% following wartime spending.
"Right now we're creating a deficit of $1 trillion a year and debt as a percentage of GDP is rising very rapidly," Alan Greenspan, former Federal Reserve chairman, said in a 2018 interview. The economist, who died this week at age 100, warned that the next recession would be "driven by the fact that debt is rising dramatically."
The milestone reflects persistent fiscal deficits that have continued even during periods of economic expansion. The Treasury has borrowed more than $1 trillion annually in recent years, with interest payments on the national debt consuming a growing share of federal revenue. Debt-service costs now exceed spending on defense and Medicare, according to Congressional Budget Office data.
The 90% threshold carries particular weight in policy debates. Economists Carmen Reinhart and Kenneth Rogoff found in their landmark 2010 study that countries with debt-to-GDP ratios above 90% tend to experience slower growth, though the finding has been debated and refined. The current ratio surpasses that level by 10 percentage points, placing the US in territory that historically correlates with reduced fiscal flexibility.
The Interest Burden
Higher debt levels translate directly into higher borrowing costs for the government. The yield on the 10-year Treasury note, a benchmark for federal borrowing, has averaged above 4% this year, up from near-zero levels as recently as 2022. Each percentage point increase in rates adds roughly $300 billion to annual interest costs over time, according to Committee for a Responsible Federal Budget estimates.
Those costs compound the fiscal challenge. The Treasury paid more than $1.1 trillion in net interest in the past fiscal year, exceeding the $820 billion spent on defense. As debt rolls over at higher rates, that figure is expected to rise further, creating a feedback loop where more borrowing begets higher interest costs.
What Comes Next
The debt trajectory has become a central issue in Washington. The Congressional Budget Office projects that debt held by the public will rise to 118% of GDP by 2035 under current law, and higher under plausible scenarios involving extended tax cuts or increased spending. Lawmakers face a series of fiscal deadlines in the coming months, including a debt-limit suspension that expires in early 2027.
For investors, the implications cut across asset classes. Higher Treasury issuance risks crowding out private investment and keeping long-term rates elevated, which pressures equity valuations and increases borrowing costs for corporations and households. Foreign holders of US debt, who own about 30% of the total, may demand higher yields as the fiscal outlook deteriorates, amplifying the pressure on Washington to address the imbalance.
This article is for informational purposes only and does not constitute investment advice.
