03.03.26 - Members of Congress are talking about a “supplemental” for the Iran war. Here’s what that means.

On Tuesday, multiple Members of Congress raised the possibility of a supplemental (read: extra) appropriations (read: money) bill to fund the unfolding Iran war. 

Here’s what you need to know should President Trump ask Congress for extra taxpayer dollars for this purpose. For more background, check out our Monday update. 

What are supplemental appropriations? 

Supplemental appropriations just means extra money that Congress greenlights on top of the regular government funding process. Congress routinely approves supplemental appropriations for unexpected needs, such as hurricane relief or the COVID response. Supplemental appropriations for the Iran war would come on top of the current $1 trillion defense budget.  

Is this what people are talking about when they say Congress hasn’t authorized this war? 

No, “authorizations” and “appropriations” are different. When Congress authorizes something, it’s giving the federal government the authority to take action. When Congress appropriates, it’s paying for an action. 

When people say Congress has not authorized military action against Iran, they’re referring to passing an authorization for the use of military force (AUMF), like the ones Congress approved after September 11, 2001 and for the Iraq War in 2002. Under Article I of the Constitution, only Congress has the power to declare war—however, presidents have repeatedly sidestepped this requirement and conducted military operations without congressional approval, as President Trump did this weekend. 

Does Congress ever give the President extra money for war? 

Yes. Congress passed several supplemental appropriations packages for the Afghanistan and Iraq Wars. These extra funding pots came with fewer strings than normal appropriations bills, such as budgetary caps and spending deadlines. The Bush administration earned lawmakers’ bipartisan rebukes for failing to provide detailed plans or justifications for these billions of extra taxpayer dollars.

How much could the President ask for? 

We don’t know. An analysis from the Center for American Progress released Tuesday estimated that, since Saturday, the war had already cost taxpayers $5 billion.

It’s worth noting that, less than a year ago, the President and Republicans in Congress passed massive cuts to health care and food assistance that will take health coverage from 10 million Americans and take food aid from 4 million. Just as spending on this war begins, those cuts are beginning to take effect.

How much could this war cost long-term? 

We don’t know. Brown University’s Cost of War Project estimates that the U.S. spent more than $2 trillion on the war in Afghanistan between 2001 and 2019, and more than $2.89 trillion on the wars in Iraq and Syria between 2003 and 2023. 

How would lawmakers vote on a supplemental appropriations request? 

This isn’t clear, either. House Democratic Leader Hakeem Jeffries decried “the nerve” of the administration for raising the issue at all. Senators Sanders and Gallego were similarly opposed. 

A supplemental request would offer an important opportunity for Members of Congress who oppose these military operations. Voting against more money for war would both indicate their positions on-the-record and, in sufficient numbers, could even deny the President funds to prolong the war. 

So, should the President send Congress a supplemental funding request, this will be a critical vote to watch. We’ll keep you posted. 

If you’d like a live update for your group or coalition, reach out to catherine@webuildprogress.org. Thanks!