I don't believe they have yet, but what scenario would play out should Iran declare a "state of war" against the US? According to the War Powers Act, Congress alone has the ability to declare war. Although, the War Powers Act was ignored by President Obama on two separate occasions, once in Libya and once in Syria. The War Powers Act was was also invoked in 2018 by Bernie Sanders (I-VT), Chris Murphy (D-CT), and Mike Lee (R-UT) in regard to Yemen, It was vetoed by President Trump. War Powers Resolution - Wikipedia So what occurs if Iran declares a state of war against the US? Does Congress reciprocate by invoking the War Powers Resolution? And does President Trump sign the resolution or veto it?