Passed unanimously in the House of Representatives on Tuesday night, an amendment to the National Defense Authorization Act (NDAA) for 2019, which itself passed the House on Thursday, warns the Trump Administration that they have no legal authorization for a military attack on Iran.

The amendment was offered by Rep. Keith Ellison (D-MN), and was very simply worded. It simply declares that it is the sense of Congress that neither the NDAA nor any other act authorizes the use of military force agaist Iran.

The amendment became particularly important after President Trump withdrew the US from the P5+1 nuclear deal with Iran. Analysts have warned that this move, followed by a litany of demands from Secretary of State Mike Pompeo, was setting the stage for a US war.

Rep. Ro Khanna (D-CA) said the amendment sends a clear message to the Trump Administration that “Congress has the power to decide issues of war and peace.” Whether this remains in the final version of the NDAA remains to be seen.

The Senate version does not appear to contain a comparable amendment, and that means it is possible that the final reconciled House and Senate version of the NDAA might remove this language. Given a number of outspoken hawks and a unanimous vote, it seems likely many are expecting this amendment won’t survive the final bill.