Trump's War of Choice in Iran Has Cost US Taxpayers Over $10 Billion in Just 10 Days

The cost of President Donald Trump's unprovoked and unconstitutional war with Iran has already cost US taxpayers billions of dollars, and will cost billions more if the conflict drags on.

Anadolu Ajansı on Monday published an estimate that the Iran war cost $10.35 billion over its first 10 days, or more than 1% of the entire 2026 US defense budget.

The US spent an estimated $779 million in the war's first 24 hours alone, and Anadolu noted that daily costs have gone up since then.

Specifically, Anadolu found that as "the campaign has expanded, operational spending has climbed into the billions, based on estimated flight hours, maintenance costs, and munitions expenditures derived from the US Department of Defense’s 2025 and 2026 budget requests."

In the days since Anadolu published its estimate, the estimated cost of the war has soared past $11 billion, according to a tracker that assumes the assault is costing the US $1 billion per day, based on preliminary figures from the Pentagon.

The Washington Post reported on Monday that the US Department of Defense estimated that it burned through $5.6 billion worth of munitions in the initial strikes on Iran, raising questions about whether the war has seriously eroded US military readiness.

Due to the conflict's rapidly escalating costs, the Trump administration is expected to ask US Congress for a $50 billion supplemental funding bill to keep the war going.

Bobby Kogan, senior director of federal budget policy at the Center for American Progress, and Damian Murphy, senior vice president of national security and international policy at the Center for American Progress, released a memo on Monday explaining why Congress should not agree to any White House requests for supplemental funding.

First, the memo notes that polling shows that the Iran war is unprecedentedly unpopular, being the first US war ever to have a net negative approval rating at the outset of the conflict.

"Lawmakers in Congress have the upper hand both morally and politically in opposing the war in Iran," the memo states. "The public does not want to be drawn into another forever war that threatens American lives, kills children, destabilizes the Middle East, and whose costs could easily balloon to hundreds of billions or even trillions of dollars."

The memo then argues that the massive increase in defense spending contained in the One Big Beautiful Bill Act, which was passed by Republicans in last year and signed into law by Trump, should be more than enough to cover the cost of replacing munitions.

"The 'Big Beautiful Bill' provided an additional $153 billion for defense just eight months ago," the memo explains, "on top of the annual defense budget of around $900 billion. The annual defense appropriations bill, also approved only a few months ago, grants the White House the legal authority and flexibility to move around billions of dollars within the Department of Defense to achieve their goals, known as transfer authority."