Era of Cheap US Debt Ends as $40T Burden Strains Global Markets

The United States crossed a threshold in August that few thought would arrive so quickly: $40 trillion in national debt. The number itself is abstract until you consider what it means in real time. The country now spends more than $1 trillion every year just paying interest on what it owes—over $3 billion per day. Since 2024, that interest bill has exceeded the entire military budget. Thirty years ago, in 1996, the total national debt was $5.2 trillion. The debt has grown 650% in three decades, but the acceleration is what should catch your attention: it took until 2008 to reach $10 trillion, then nine more years to hit $20 trillion in 2017. By early 2022, the country owed $30 trillion. The final $10 trillion took just four and a half years.

Global investors are noticing. Norway's sovereign wealth fund, the world's largest pension fund, announced in September that it would cut its holdings of US government bonds by $80 billion—a reduction from the $215 billion it held at the end of June. When the largest institutional investor in the world starts pulling back, others take note. The yield on 30-year Treasury bonds has climbed to nearly 5.4%, the highest level since 2007. That higher yield means the US government will pay more to borrow money going forward, which only worsens the spiral.

Treasury Secretary Scott Bessent has acknowledged the problem. He announced plans to triple the volume of long-term government bond buybacks from $2 billion to as much as $6 billion per month, an attempt to artificially suppress yields and keep borrowing costs down. Analysts were blunt about the measure's inadequacy. Carsten Roemheld, a capital market strategist at Fidelity International, told Deutsche Welle that the buyback program is "far too small on its own to truly keep yields in check over the long term." Bessent has also stated a goal of cutting the budget deficit in half, but economists view this as unrealistic given the enormous cost of the ongoing Iran war, combined with revenue shortfalls from corporate tax cuts and tariffs that the Supreme Court struck down.

The deficit is on track to reach nearly 6% of GDP in 2026. Roemheld noted that nervousness is rising sharply within the US administration itself. "If this trajectory continues, it will be very difficult to sustain," he said. The comparison to other wealthy nations is instructive. Germany's debt-to-GDP ratio sits around 65%, roughly half that of the United States. Japan carries a far heavier burden—debt exceeding 200% of economic output—and borrowing has become increasingly expensive there. Italy, France, and the UK all face similar pressures as investors demand higher yields to compensate for perceived risk.

Yet the United States retains a structural advantage that keeps investors coming back despite their concerns. There is no viable alternative. Carsten Brzeski, chief economist at ING Bank, explained that the European capital market cannot yet serve as a substitute for US markets, and China and other emerging economies are neither able nor willing to fill that role. "That is why I believe investors—even though they currently fear higher inflation and question the sustainability of US sovereign debt—will not turn away from the US," Brzeski told DW. "At least not as long as the US economy is growing." Fidelity's Roemheld agrees that default is unlikely; the US can simply print money to pay its debts. But that solution carries its own cost. "This course of action will undermine confidence," he said, "and one outlet for this is the dollar exchange rate, which suffers when international investors become less willing to continue providing dollars to the US."

A new competitive pressure is emerging that could accelerate the problem. Major technology companies are issuing bonds at record pace to finance artificial intelligence infrastructure. The four largest "hyperscalers"—the companies building platforms for the US AI industry—have already raised over $800 billion in debt this year, with that figure expected to climb further. These corporate bonds offer investors something US Treasuries increasingly cannot: higher yields with acceptable risk. A long-term bond from Alphabet or Microsoft might offer a spread of 100 basis points above Treasury yields, making them genuinely attractive alternatives for investors who once held government bonds primarily for safety. As Robert Sockin, chief US economist at asset manager PGIM, noted, AI-related corporate bonds are "increasingly crowding out government bonds" in investor portfolios. The longer the Iran war continues, driving military spending and energy prices higher, the more likely it is that the US will face sustained pressure to pay higher interest rates on capital markets. For now, the dollar's dominance keeps the system functioning. But the era of cheap American debt has ended, and the question facing policymakers is whether the political will exists to address the underlying problem before confidence erodes further.