A coalition of 28 congressmen, including both Republicans and Democrats, is championing an amendment to the defence authorisation bill, which would prohibit the use of funds for military action against Iran without prior approval from Congress.
In a letter to the Senate and House Armed Services Committees obtained by Foreign Policy, senators and representatives expressed their concerns that the risk of the United States entering a war with Iran without authorisation is “acute”.
“Bipartisan majorities in both chambers have spoken up to defend Congress’ constitutional authority over matters of war and peace,” the lawmakers wrote.
“We have no illusions about the potential threats that Iran may pose, or its destabilising activities in the Middle East. These bipartisan amendments do not interfere with the United States Armed Forces’ ability to defend themselves,” they added, addressing concerns that the amendment could affect the military’s ability to quickly respond to potential security threats. “But under our constitution, any war requires congressional authorisation.”
The push for curtailing Trump’s war powers reportedly saw Republican supporters of Donald Trump, such as Florida Rep. Matt Gaetz, join forces with his Democratic critics, including New Mexico Senator Tom Udall and California Rep. Ro Khanna.
“This is the most urgent national defence issue we are discussing in Congress, and it’s this rare issue where you have real bipartisan agreement and also very strange bedfellows from the farther right and farther left,” an unnamed congressional aide was quoted as saying.
On 12 July, the House passed a similar amendment to the fiscal 2020 National Defence Authorisation Act that would prohibit the Trump administration from funding military action against Iran without authorisation. It was passed in a 251-170 vote that drew 27 Republicans, and has yet to be approved by senators.
Rep. Ro Khanna, who co-sponsored the bill, called it "the most important foreign policy vote in the United States Congress".
Another similar measure languished in the Republican-controlled Senate; the final vote tally was 50 in favour to 40 against the amendment, which stopped short of meeting the 60-vote threshold.
The House and Senate have published their versions of the defence policy bill, supporting $733 billion and $750 billion for military programmes, respectively.
The House bill, adopted by a Democratic majority through a strict party-line vote, would block the Trump administration from using military funds for a border wall, ban emergency arms sales to Saudi Arabia, end US military support to the Saudi-led coalition in Yemen, prohibit military parades for political purposes, and prevent the transfer of new prisoners to Guantanamo Bay.
The Senate has included none of those provisions, and the two parties have yet to face difficulties reconciling their versions in the fall.
Tensions between the United States and Iran continue to run high, with Washington seeking an allied naval coalition following a series of incidents in the Gulf of Oman in recent months.
The US accused Iran of attacking foreign oil tankers in May and June – something Tehran denied. Washington later condemned the seizure of tankers by Iran’s Revolutionary Guards in the Strait of Hormuz, one of the world’s most important waterways.
In June, Trump ordered and called off, at the last minute, an air strike against Iran after the downing of a US spy drone, which could have led to a full-scale military conflict.