5 Reasons the US Should Not Spend Another Penny on the War with Iran

Benjamin Giltner and Dominik Lett

Reports suggest that the Trump administration is drafting an emergency funding request of up to $50 billion to support the war in Iran. The US has already spent an estimated $19 billion on this conflict. Before Congress commits to any more spending, here are five reasons lawmakers should hesitate in financing yet another overseas conflict.

1. The Administration Is Pursuing an Undefined War with No Clear Exit

Before going to war, policymakers must determine the end goals. The Trump administration fails to define these end goals and seems inclined to change them day by day. 

Initially, the Trump administration supported the overthrow of Tehran’s government and the complete destruction of its nuclear materials and ballistic missile capabilities. More recently, President Trump indicated that the war could end “soon” as there is “practically nothing left,” despite Tehran remaining capable of reconstituting its forces and being more inclined now to build a nuclear weapon. 

Without clearly defined war aims, it’s impossible to know what victory looks like or how much it will cost to achieve it. Congress should avoid authorizing $50 billion for a conflict with ill-defined objectives.

2. “Mowing the Lawn” Is not a Strategy

Short of adopting clear war aims, the administration seems to have settled on a “mowing the lawn” approach—a strategy that involves periodically striking Iran’s military capabilities without seeking a decisive outcome. 

This is a recipe for endless bombing—or endless war—for the US. Prior adventurism justified on similar terms should serve as a stark warning of the futility of such an approach. Per Neta Crawford, the total fiscal burden from the global war on terror exceeds $8 trillion. A $50 billion Iran war supplemental today may all too easily spiral into an indefinite, large fiscal commitment.

3. Costs Are Already Steep, and Inventory Is Hard to Replace

To date, the US has already spent an estimated $19 billion in only two weeks of fighting. Much of what a war supplemental would fund, primarily missile defense munitions, is expensive and difficult to replenish.

Consider THAAD interceptors. Each missile interceptor costs roughly $12.7 million. The United States produces roughly 22 of these THAAD interceptors each year and maintains a stockpile of approximately 646 interceptors. In its last conflict with Iran during the Twelve-Day War, the United States used 100 to 150 THAAD interceptors, roughly 15 to 20 percent of America’s entire stockpile. 

At current production rates, rebuilding the THAAD missile inventory will take years. Funding further conflict in Iran will accelerate the depletion of these hard-to-replace and costly assets.

4. An Emergency War Supplemental Is Irresponsible Fiscal Policy

Emergency spending is supposed to be for issues that are vital, sudden, urgent, unforeseen, and non-permanent. A war that the administration initiated, is actively planning, and may drag on far into the future fails most of those criteria from the outset. 

Consider that between FY2001 and FY2023, Congress used emergency supplementals and specially designated “non-base” budget categories to fund nearly one-fifth of all defense spending, amounting to $2 trillion in nominal terms. Viewed in isolation, an individual supplemental may seem like a drop in the bucket. But viewed together, overreliance on war supplementals can have a large long-term fiscal impact.

Because emergency spending is exempt from many conventional budget controls, like spending caps, it also faces less oversight than other categories of discretionary spending. In 2017, the Government Accountability Office reported that the flawed criteria underlying past emergency defense spending surges “hindered [decisionmakers] in their ability to set priorities and make funding trade-offs.” Put differently, relying on emergency spending supplementals to finance conflicts results in worse strategy and more overspending.

A $50 billion Iran supplemental is likely to repeat this pattern.

5. Economic Power Underwrites Military Power

Across history, countries whose government spending outpaces their economic means face degradation and eventual collapse. This fact is unavoidable for the United States. Yet the fiscal environment for the US has rarely been worse.

Deficits are $2 trillion and mounting. Federal public debt is on track to exceed the size of the US economy this year. Interest costs on America’s debt are exceeding federal spending on national defense. This deteriorating fiscal outlook, primarily driven by old-age entitlements, gets even worse if you factor in another protracted episode of military adventurism. In short, spending restraint is needed now more than ever.

Despite this, the recently enacted One Big Beautiful Bill Act (OBBBA) included more than $175 billion in defense spending on top of an $839 billion base discretionary defense budget. Amid these routine $2 trillion federal deficits, spending another $50 billion on this supplemental and $1.5 trillion for Trump’s proposed FY2027 defense budget is imprudent.

Greater defense spending now begets higher defense spending in the future, boosting deficits, raising borrowing costs, and producing worse long-term economic outcomes. A country can’t have military power without economic power. If lawmakers care about national security, they should make the national debt a higher priority issue. They can start by rejecting unwarranted defense spending. 

Old Habits Die Hard

The war in Iran is not worth fighting. If Congress wants to deficit-finance yet another Middle East conflict, they should at least be honest about what it is they are doing: transferring wealth from current and future generations to finance a conflict characterized by shifting objectives, no exit plan, and an ever-growing price tag. Emergency supplementals with no offsets and no defined exit strategy are exactly how the US wound up spending trillions of dollars on post‑9/​11 military adventurism. Congress should not repeat that mistake.