US President Donald Trump launched a military operation against Iran with Israel on the grounds that there was an immediate threat to the United States.
In his speech, he stressed that the action was necessary to protect national security.
However, on Capitol Hill, members of Congress began to raise the issue of the determination of the powers of a US President that exceeded the limits of national law.
According to the US Constitution, the power to declare war lies with the United States Congress, not the president.
Although there is a 1973 law known as the War Powers Resolution that allows the president to act in a state of emergency, the operation cannot last more than 60 days without the approval of Congress.
Senator Tim Kaine is one of the most vocal critics of the action.
He described the war as unnecessary and wanted Congress to vote immediately to determine whether the operation should continue. For him, a decision of this magnitude cannot be made by the president alone.
Another senator, Mark Warner, also questioned the reason for the threat. He said there was no clear evidence that Iran had attacked or was about to attack the United States.
If the threat to Israel is considered the same as the threat to the US, it would set a worrying new precedent.
Interestingly, the opposition is not just coming from Democrats. Republicans Thomas Massie and Ro Khanna plan to introduce a bill in the House of Representatives to force a formal vote.
They want every member of Congress to be on record as supporting or opposing the war.
But the reality is that a majority of Republicans are expected to side with Trump. Even if the bill passes, the president can still use his veto power.
Overriding a veto requires the support of two-thirds of members in both chambers, which is rare in today's divided political climate.
