Tariffs are generating only 25% of the revenue needed to pay interest on national debt—despite pitch that it would be a silver bullet

When President Trump announced his plans for a new tariff regime, he said the action was “primarily to pay down debt, which will happen in very large quantity.” But fast-forward a little under a year, and the revenues generated by customs duties aren’t enough to make a dent in interest payments on national debt—let alone the headline figure.

As of June 2026, U.S. national debt stands at $39.2 trillion, according to Treasury data. That figure is growing by eye-watering sums: For the first eight months of fiscal year 2026, the Congressional Budget Office (CBO) reports the federal budget deficit has totaled $1.2 trillion.

In its monthly budget review published last week, the CBO also broke down the government’s incomings versus its outgoings: For the first eight months of the fiscal year (which ends in September), the government raked in $3.66 trillion but spent $4.9 trillion.

Income rose quicker than spending, the CBO reported, with revenues increasing by $174 billion, while spending crept up $57 billion.

However, income would need to rise significantly to have any impact on the value of interest payments the Treasury is paying to maintain debt levels.

The C...