Senate Republicans Want to Block the Iran Deal. Here Is What They Can — and Cannot — Actually Do.

Senators Lindsey Graham of South Carolina and Roger Wicker of Mississippi said Sunday they intend to fight the Iran nuclear deal being negotiated by the Trump administration. Graham called it dangerous. Wicker called it a disaster. Neither senator, however, named the specific legal mechanism that Congress has to constrain what the executive branch can sign.

That mechanism exists. Congress wrote it into law in 2015, in direct response to a previous president’s Iran nuclear agreement. And as the framework Trump announced Saturday moves toward a formal signing — whenever that comes — understanding what that law actually does, and what it doesn’t do, matters more than the volume of any senator’s objection.

What INARA Requires

The Iran Nuclear Agreement Review Act of 2015 — INARA, pronounced as spelled — was signed into law on May 22, 2015, with overwhelming bipartisan support. Congress passed it by veto-proof margins: 98–1 in the Senate and with overwhelming bipartisan support in the House. Its core requirement is simple: before any agreement between the United States and Iran that relates to Iran’s nuclear program can take effect, the President must submit that agreement to Congress, and Congress gets 60 calendar days to review it.

During that review window, the President cannot waive, suspend, reduce, or otherwise limit any statutory sanctions on Iran. The administration cannot begin implementing the deal. The Strait of Hormuz cannot legally be reopened under a sanctions-dependent framework while the 60-day clock is running.

Congress can use those 60 days to pass a joint resolution of disapproval. If both chambers pass one, the President can veto it. Overriding the veto requires a two-thirds majority in each chamber — 67 Senate votes and 290 House votes. If the override fails, the deal proceeds. If Congress cannot even pass a disapproval resolution in 60 days, the deal also proceeds.

The law was designed to give Congress a formal say in major nuclear diplomacy with Iran without requiring the deal to go through Senate ratification as a treaty, which would require a two-thirds vote just to ratify rather than a two-thirds vote to override a veto of disapproval. The distinction matters: it’s a lower bar for the executive than treaty ratification, but it’s still a bar.

The Threshold Question: Does This Deal Trigger INARA?

The law covers “any agreement with Iran, including a side agreement, implementing agreement, particular plan, or other document that is entered into or implemented in connection with the subject matter of any agreement” — where “subject matter” means “the nuclear program of Iran.”

The deal described by Axios — a 60-day memorandum of understanding that includes a nuclear moratorium provision — would, on its face, appear to qualify. According to officials familiar with the text, the MOU would commit Iran to entering separate negotiations over a halt to uranium enrichment, with a 12-to-15 year moratorium as the working landing zone. The nuclear provisions are explicitly part of the package being signed, not a downstream negotiation left entirely to a later document.

The Trump administration has not yet publicly addressed whether it considers INARA to apply.

That question is not as simple as it sounds. In 2015, the Obama administration’s position was that INARA applied to the Joint Comprehensive Plan of Action (JCPOA) even though the JCPOA was technically a political commitment rather than a legally binding treaty — and Obama submitted it to Congress anyway, in part because Congress had just passed INARA by a veto-proof margin and the political costs of ignoring it were too high.

The Trump administration in 2026 faces a different political calculus. Republican senators are the loudest critics, not Democrats. The White House might argue that a 60-day MOU framework is a preliminary document — not a final “agreement” with Iran relating to its nuclear program — and that formal INARA submission applies only when a permanent deal is signed. That interpretation would give the administration 60 more days to work out the permanent deal before the review clock starts.

Whether that argument is legally sound is a separate question from whether anyone would successfully enforce a different reading. Courts have historically treated nuclear diplomacy disputes as political questions outside judicial review.

What the 2015 Precedent Actually Shows

The JCPOA review in the summer and fall of 2015 is the only time INARA has ever been used. That history is instructive, and not in the way critics of the current deal might hope.

Obama submitted the JCPOA to Congress on July 19, 2015. The 60-day clock started that day. Republicans controlled both chambers. Senate Majority Leader Mitch McConnell of Kentucky brought a resolution of disapproval to the floor in September.

What happened next is not widely remembered: Democrats used procedural means — specifically, refusing to vote for cloture on the motion to proceed — to prevent the disapproval resolution from ever reaching a final vote. When the Senate voted in September 2015 on whether to proceed to debate, the motion failed to reach the 60 votes needed to end debate. The final tally was 58 senators in favor of proceeding, 42 opposed. The resolution died. Obama never had to veto anything. The 60-day window expired without Congress passing a disapproval resolution, and the JCPOA went into effect.

The lesson: INARA’s formal process gives Congress a window and a mechanism. It does not guarantee that either chamber can actually use the mechanism, particularly when the minority party — in 2026, that’s Senate Democrats — has procedural tools to run out the clock.

What Graham and Wicker Can Actually Do

The Senate currently has 53 Republican members. Vice President JD Vance can break ties, giving the caucus an effective 54-vote working majority. INARA includes expedited procedures that limit debate on the disapproval resolution itself once the Senate is actually considering it — but reaching that point requires the Senate to first agree, by 60 votes, to proceed to consideration. In 2015, that procedural step was where Democrats blocked the process, preventing a final vote on disapproval by refusing to vote for cloture on the motion to proceed.

That matters for 2026: if Senate Democrats hold together and refuse to provide cloture on the motion to proceed, Graham and Wicker cannot force a final vote on disapproval even with 53 Republican votes. They would need seven Democratic senators to agree just to bring the resolution to the floor — and then, if a disapproval resolution somehow passed both chambers, the President would veto it. Overriding that veto requires 67 Senate votes. Republicans have 53. Given that Senate Democrats were united in blocking the 2015 disapproval of the Obama-era deal, the prospect of 14 Democrats crossing over to help override a Republican president’s veto of his own deal is essentially nonexistent.

Graham and Wicker know this. Their objections are not naïve — both have been in the Senate long enough to understand the arithmetic. What they are doing is more strategic: establishing early, clearly, and loudly that they believe the deal’s terms are inadequate, in hopes of pressuring the administration to strengthen those terms before a final agreement is signed. Their leverage is not in voting down a deal. It is in making the political cost of a weak deal higher for an administration that needs Republican unity on other legislation, including the Big Beautiful Bill’s fraught Senate path.

What Happens If Trump Doesn’t Submit the Deal at All

If the administration decides the MOU doesn’t trigger INARA — or simply doesn’t submit it — Congress’s options narrow significantly.

Democrats could introduce a resolution demanding submission and call for a vote. That vote would fail on party lines. Republicans who disagree with the president could add their voices to the demand — Collins, who broke with her caucus on the War Powers deadline that expired in early May, has shown she’s willing to go on record against the administration on Iran. But a non-binding demand has no enforcement mechanism.

Courts have not resolved the question of whether INARA is judicially enforceable. The Congressional Research Service noted in its 2015 analysis that it was “unclear” whether Congress could compel submission through litigation, and no court has since clarified the question. The statute gives Congress a review process if the President chooses to trigger it; it does not obviously give courts the authority to force him to.

The practical outcome, in that scenario, would be the deal proceeding — along with escalating political conflict between the Republican-controlled Senate and a Republican White House, an unusual dynamic that would test both sides’ appetite for confrontation.

What Happens Next

The Senate returns from Memorial Day recess Tuesday. Rubio — who met Indian Prime Minister Modi Saturday and attended the Quad Foreign Ministers meeting in New Delhi — said Sunday he expected a deal announcement soon. As of Memorial Day evening, no formal announcement had been made.

If a deal is announced this week, INARA’s five-day submission clock — the window in which the President must send the agreement to Congress after signing — starts immediately. The Senate Foreign Relations Committee, chaired by Sen. Jim Risch of Idaho, would have jurisdiction over the review. Risch has been skeptical of the deal but has not yet declared whether he would call a formal hearing.

The question of whether this deal goes through INARA at all may turn on a narrow legal argument about whether a 60-day MOU counts as the kind of “agreement” INARA was written to capture. If the administration says it does not, the senators making the loudest noise about fighting the deal will find themselves with a less formal fight on their hands — one conducted through floor speeches and television appearances rather than through the legal machinery Congress built specifically for this purpose.

The machinery exists. Whether either side is willing to use it is the question that Memorial Day did not answer.