Democratic senators are questioning the Pentagon's rising cost estimates for the war against Iran and the use of approved funds.

The dispute highlights a growing tension between the administration's military spending requirements and congressional oversight regarding taxpayer burdens during an active conflict.

U.S. Defense Secretary Pete Hegseth said the cost of the war on Iran is now $37.5 billion [1]. This figure represents a significant increase from the estimate of approximately $29 billion provided in mid-May [2].

During proceedings in the U.S. Senate in Washington, D.C., Sen. Jen Shahin (D-NY) challenged the necessity of requesting additional resources. Shahin pointed to a pool of $75 billion in funds that Congress had already approved, but which the Pentagon has not yet spent [3].

"Why are you asking the American people to bear the cost of a war they don’t support, instead of demanding the transfer of already‑approved but unspent funds?" Shahin said.

The senator argued that the government should prioritize the utilization of existing appropriations before seeking further financial burdens from the public. This critique comes as the costs of the engagement continue to climb, a trend that has drawn scrutiny from lawmakers concerned about long-term fiscal commitments in the region.

Hegseth's updated figures reflect the volatile nature of the conflict's financial requirements. However, the discrepancy between the current $37.5 billion cost [1] and the $75 billion in available unspent funds [3] remains the central point of contention for the Democratic delegation.

The cost of the war on Iran is now $37.5 billion, up from about $29 billion in mid‑May.

The confrontation between Sen. Shahin and Secretary Hegseth signals a shift toward stricter fiscal accountability for military operations. By highlighting the $75 billion in unspent funds, lawmakers are attempting to constrain the Pentagon's ability to request new appropriations, potentially limiting the scale or duration of the conflict if existing funds are treated as a hard cap.