Defense Secretary Pete Hegseth, in a Senate Appropriations Committee hearing on Tuesday, put the cost of the war with Iran at $37.5 billion to date - while saying that a further $1.5 trillion was necessary for the adequate defense of the United States.

"Not funding this department at $1.5 trillion, I believe, is the greatest threat that our nation faces," he said.

Hegseth, who was interrupted by protestors in the congressional chambers who shouted things like "Stop bombing our children in Iran and Palestine!" and "End this war right now!" before the Capitol Police was called upon by Senator Collins, made his case for an additional $67 billion in supplemental funding for the war with Iran.

"The military requires a generational investment to deliver on peace through strength. We know the best way to create peace is to prepare for war, to deter it, and that's exactly what the Department of War is doing, building a force so capable that it would be absurd for anyone to challenge it," said the defense secretary.

"Without these funds, we face critical shortfalls that threaten our ability to also simply pay our service members, rapidly replenish equipment and munitions, and sustain vital operations without disruption."

US Secretary of Defense Pete Hegseth looks at U.S. Chairman of the Joint Chiefs of Staff General Dan Caine during a Senate Appropriations Committee hearing on US President Donald Trump's supplemental funding request for the Department of Defense, in Washington.
US Secretary of Defense Pete Hegseth looks at U.S. Chairman of the Joint Chiefs of Staff General Dan Caine during a Senate Appropriations Committee hearing on US President Donald Trump's supplemental funding request for the Department of Defense, in Washington. (credit: Eric Lee/Reuters)

One-off supplementals are not enough, says Hegseth, but it'll do for now

He went on to say that "$1.5 trillion is what the President seeks and what we need to defend the country. The members of this committee understand better than most that long-term strategic dominance cannot be funded through one-off supplementals," while requesting billions in various forms for the immediate implementation for the armed forces.

"On the readiness front, we requested $21 billion. This will fund military pay, replace much of the equipment utilized during recent operations, sustain forward-deployed forces, and grow personnel and strength while stabilizing mission-critical fuel shortfalls and supporting the National Guard," he said.

Hegseth emphasized that funds would also go to upgrading, modernizing, and replenishing the US armed forces.

"This supplemental request serves two purposes: Sustain our military readiness to meet this year's new demands, and accelerate critical capabilities to replace and augment those we have used in contingencies."

Biden administration one of 'sheer weakness'

He also criticized the Biden administration for handing off a weakened defense infrastructure.

"President Trump inherited a set of global and domestic crises. Deferred maintenance almost across the board. Instead of steering the ship through gathering storms, former leaders let our military languish through social experiments and globalist appeasement, sheer weakness."

Continuing on, the defense secretary said that "The Pentagon is no longer run by bureaucrats; instead, it's led by combat-tested veterans and world-class business leaders, who are running the department like a business. And tech titans who are bringing lethal innovation to the battlefield. We're also at a different moment, and we cannot afford inaction. If we don't make critical investments right now in tech, in compute, in AI, in autonomy, in space, our adversaries who are already making these types of investments could outpace us."

Although Hegseth estimated a cost of $37.5 billion, NBC News reported this month that the cost of the war lies somewhere between $80 billion and $100 billion when including the cost of repairing damaged US bases and replacing destroyed or spent American aircraft and weaponry.