Debt Service Now Costs More Than the Pentagon
The United States now spends more servicing its debt than it does on national defense. That inversion, documented in the GAO’s March 2026 federal debt management report (GAO-26-107529), is not a rhetorical comparison. It is a statement about the structure of the federal budget and what it means for fiscal flexibility going forward.
Net interest costs in fiscal year 2025 exceeded $970 billion, or 3.2 percent of GDP. That figure represents the highest share in the post-war record. In fiscal year 2014, net interest was $229 billion, 1.3 percent of GDP. The decade-long trajectory is not a spike — it is a structural shift driven by two compounding forces: a larger debt stock and a higher interest rate environment. The average interest rate on marketable Treasury securities was 2 percent at the end of fiscal year 2014. By the end of fiscal year 2025, it was 3.4 percent. The 10-year Treasury yield as of September 2025 stood near 4.2 percent.
The GAO’s forward projection, built on CBO data released in December 2024, is more unsettling than the current snapshot. On the current fiscal path, interest costs are projected to exceed the 3.2 percent historical high in the near term and reach approximately 8 percent of GDP by 2053. That would mean nearly one dollar in ten of national economic output going to debt service — before a single dollar of discretionary policy is spent.
The defense comparison matters because it surfaces a real trade-off. Every dollar spent on interest is a dollar not available for military readiness, infrastructure, healthcare, or emergency response. The GAO puts it plainly: growing interest costs impair the government’s ability to respond to recessions, public health crises, military conflicts, and natural disasters. That is not a hypothetical. It is a description of reduced fiscal room at the exact moments when governments most need it.
The interest bill also has a self-reinforcing quality. Higher debt produces higher interest costs, which increase the deficit, which requires more borrowing, which increases debt. That feedback loop is not theoretical at this scale — it is already in motion. The CBO’s projections assume no major new policy changes. They are not pessimistic scenarios. They are the baseline.
What changes the trajectory is either lower deficits — through some combination of revenue increases and spending restraint — or lower interest rates, which the Federal Reserve controls and which debt managers cannot engineer. Treasury’s role is to finance whatever gap the political system produces at the lowest achievable cost. That role has no mechanism for correcting the gap itself.
A defense budget larger than the interest bill was a proxy for fiscal health. That proxy is now inverted, and no one in a position to fix it has scheduled the meeting.