US debt interest now costs more than defence

Defence spending is not cheap. It buys soldiers, aircraft carriers, missile systems, bases, intelligence networks, logistics, cyber capability and the vast machinery of American military power. You can argue about whether the US spends too much on defence, too little, or spends it badly. But at least defence spending buys capacity. It buys something the state can use.

Interest payments are different. They are the bill for past borrowing. They do not build a road, modernise a school, fund a hospital, strengthen the military, secure the border, rebuild an airport or invest in research. They mostly compensate creditors for lending money to the US government. Some of those creditors are American pension funds, banks, insurers, households and public institutions, so the money does not simply vanish overseas. But that does not change the basic point. Interest is the cost of decisions already made. This is not a story about the US going bankrupt. That argument is too crude. America borrows in its own currency. It issues the world’s dominant reserve asset. There is still enormous global demand for US Treasuries. The US has a deep capital market, a huge tax base and extraordinary economic power. It is not Greece. It is not Argentina. It is the issuer of the dollar.

But that does not mean debt is free. The danger is not sudden insolvency. The danger is constraint. When interest becomes one of the largest items in the federal budget, it starts to crowd out everything else. Every dollar spent servicing old debt is a dollar that cannot easily be used for tax cuts, infrastructure, healthcare, education, welfare, industrial policy, defence or emergency spending. It also makes government less flexible. Congress can trim a programme, delay a procurement cycle, cut a grant or argue about entitlement reform. Interest has to be paid. It is largely determined by the existing stock of debt and by the interest rate investors demand to hold that debt.

That is what makes the chart so striking. For decades, defence spending sat above interest costs. Then the green line caught up. The recent surge is not just about higher debt. It is about higher debt meeting higher rates. Cheap money allowed Washington to pretend that borrowing had little immediate consequence. Higher rates have ended that illusion.

The political problem is obvious. Voters want more services, lower taxes, stronger defence and less debt. Politicians have promised some combination of those things for years. The maths is becoming less forgiving.

America remains rich. It remains powerful. It remains financially unique. But even unique countries face trade-offs. The world’s most powerful government is now spending more and more money simply to stand still. That is not bankruptcy. It is something slower, quieter and perhaps more politically dangerous: the loss of fiscal freedom.