U.S. debt concerns weigh on Trump’s plan to supersize the Pentagon’s budget to $1.5 trillion

Sources told The Washington Post that White House budget chief Russell Vought was among the critics of giving the Pentagon an additional $500 billion, warning on its potential impact on the federal deficit, which hit $1.8 trillion in the last fiscal year.

A longtime fiscal hawk, Vought has been an advocate of reducing overall government spending while also rebuilding the U.S. military, the report said.

The White House did not provide a comment. A defense spokesman told the Post that the Pentagon is committed to “utilizing President Trump’s $1.5 trillion defense budget to serve our warfighters and the American people.”

“Our deliberative and responsible budget process ensures the Department is a good steward of taxpayer resources and able to combat 21st century threats,” he added.

Other obstacles to the huge defense boost include deciding where to spend all that money as officials debate how much to invest in existing weapons systems versus emerging high-tech areas like AI, the Post said.

The Defense Department has to balance several spending priorities. It must reconstitute an aging fleet of ships and aircraft with next-generation platforms like the B-21 stealth bomber and the Columbia-class submarine. Production of the F-35 stealth fighter is also ramping up to replace a range of platforms.

On top of that, Trump has announced plans for the F-47 sixth-generation fighter that will fly alongside autonomous drones. And in December, he unveiled a concept for a new class of battleship.

Meanwhile, after years supplying Ukraine with weapons and drawing down its own stockpiles of munitions, the Pentagon must rebuild its inventory to prepare for any future conflicts, including one against a near-peer adversary like China or Russia.

Russia’s invasion of Ukraine has also unleashed a transformation in warfighting tactics, especially in the use of drones and the ability to mass produce such weapons. And tech companies like Palantir and SpaceX are driving advances in the use of AI and space-based capabilities, respectively.

“This will allow us to build the ‘Dream Military’ that we have long been entitled to and, more importantly, that will keep us SAFE and SECURE, regardless of foe,” Trump said in a Truth Social post this month regarding his $1.5 trillion goal.

But addressing all those needs will come with a high price tag, just as America’s spending capacity is coming under more strain. Publicly held U.S. debt is expected to soar from about 100% of GDP today to 120% by 2036, according to the latest projections from the Congressional Budget Office.

To be sure, soaring costs for Social Security and Medicare are the main drivers of the deteriorating fiscal outlook. But a half-trillion-dollar boost to annual defense spending would still accelerate the accumulation of debt, which entails the added costs of interest payments.

The Committee for a Responsible Federal Budget recently warned that a U.S. “debt spiral” could start soon, citing CBO estimates that show the interest rate on government borrowing will exceed economic growth in the coming years.

The White House budget chief’s reported aversion to seeing the deficit widen further on the back of a bigger military bill highlights a phenomenon observed by historian Niall Ferguson, who has said any great power that spends more on debt servicing than on defense risks ceasing to be a great power.

“This is because the debt burden draws scarce resources towards itself, reducing the amount available for national security, and leaving the power increasingly vulnerable to military challenge,” he wrote.

In fact, the U.S. hit reached this threshold in 2024 and continues to meet the conditions for “Ferguson’s Law.” Of course, ratcheting up defense outlays to $1.5 trillion would put the Pentagon budget back above debt-servicing costs, but only temporarily. Even without the added military spending, interests costs are expected to reach $2.1 trillion by 2036.