This resolution would require the President to pull U.S. military forces out of any combat involving Iran unless Congress has specifically voted to declare war or authorize that military action. In other words, it's Congress asserting that the decision to fight Iran isn't the President's to make alone. There's an exception built in: U.S. forces could still respond if the U.S. itself, or American troops or facilities elsewhere, are attacked — this measure wouldn't stop the military from defending against an actual attack. The practical effect is a check on presidential war-making power specifically regarding Iran, requiring Congress to sign off before any broader military campaign continues.