US national debt passes $40tn after doubling in a decade

The US national debt has crossed 40 trillion dollars for the first time, a milestone reached after the total doubled over the past decade. The Treasury has borrowed at an accelerating pace to fund government spending, wars abroad, and pandemic relief.

The debt explosion coincides with a sharp climb in borrowing costs. The interest rate on 30-year Treasury bonds recently hit its highest level in nearly two decades, pushing the cost of servicing the debt into record territory. The federal government now spends billions monthly just paying interest on what it owes, money that cannot be allocated to defense, infrastructure, or social programs.

The doubling of debt in ten years reflects structural shifts in fiscal policy. The 2008 financial crisis prompted emergency borrowing. The Trump administration cut taxes while raising spending. The Biden administration unleashed trillions in pandemic aid and climate legislation. Republicans and Democrats alike spent beyond revenues, relying on the Treasury market to absorb the gap.

Rising interest rates compound the problem. When the Fed raised rates to fight inflation, Treasury yields climbed accordingly. Higher borrowing costs mean future bond auctions become more expensive. The Treasury must offer richer yields to attract buyers, which locks in higher servicing costs for years ahead.

The fiscal trajectory concerns economists and bond market traders. If borrowing costs remain elevated and spending continues unchecked, debt service could consume 15-20 percent of federal revenues within a decade. That leaves less room for discretionary spending and makes fiscal adjustments harder when the next recession hits.

The 40 trillion benchmark carries symbolic weight. It underscores a decade of bipartisan deficit spending and a structural mismatch between revenues and outlays. Without tax increases, spending cuts, or economic growth strong enough to narrow the gap, the debt will keep climbing. The bond market's recent signal, reflected in those 20-year-high rates, suggests creditors are losing patience.