On the 19th, the U.S. Senate voted to advance a bill aimed at restricting President Trump's authority to use military force, requiring Trump to end military operations against Iran and to obtain congressional authorization before taking any future military action against Iran.
The vote result was 50 in favor and 47 against. Four Republican senators voted in favor, and three Republican senators were absent.
Previously, Democrats had submitted bills seven times in the Senate seeking to limit Trump’s military authority on the Iran issue. However, since Republicans hold a Senate majority, none of those bills passed.
In any case, the current bill still requires a final vote. Even so, in the Republican-controlled House of Representatives, the bill will face significant resistance to passage. The House has previously rejected similar proposals.
According to the U.S. Constitution, only Congress has the authority to declare war. In response to the U.S. military action against Iran at the end of February, multiple Democratic members of Congress criticized the action as unauthorized by Congress and therefore illegal.
On May 1, Trump sent a letter to Congress stating that the hostilities between the U.S. and Iran had ended. This statement aimed to circumvent the 60-day limit for the president to use military forces without congressional authorization.