The US House of Representatives on Thursday voted to repeal the authorisation that approved the 2003 US invasion of Iraq, after the White House this week announced that President Joe Biden intends to sign the legislation.
Members of Congress have long argued the authorisation, passed in 2002, has been used as a justification for subsequent military actions in Iraq that had nothing to do with Saddam Hussein's Baathist dictatorship.
“Given all of the countries active near Iraq today, including Turkey and Russia, the 2002 [authorisation] is vulnerable to be abused,” said Gregory Meeks of New York, the Democratic chairman of the Foreign Affairs Committee, before the vote.
Under US law, Congress must authorise military action abroad except in cases of imminent self-defence – though presidents from both parties have frequently launched strikes in countries such as Libya and Syria without congressional authorisation.
Repealing the 2002 authorisation would ensure a president can no longer use it as a legal basis for future military action in Iraq.
But a repeal would not require Mr Biden to withdraw the approximately 2,500 troops remaining in Iraq as part of the fight against the remnants of ISIS because they are stationed in the country under a separate 2001 military authorisation that Congress passed after the September 11 attacks.
“The United States is not relying on the 2002 [authorisation] as the sole authority for any military operations,” Mr Meeks said.
“It has been used as an additional legal justification for strikes by presidents of both parties, but not as the sole authority for any strikes over the last decade.”
The House passed the repeal 268-161, with 49 Republicans joining Democrats on the measure, introduced by Democrat Barbara Lee of California.
Elaine Luria of Virginia was the only Democrat to vote no.
The majority of House Republicans argued Congress should not repeal the Iraq war authorisation without replacing it, citing the fact Mr Biden’s predecessors had invoked it as an ancillary legal authority to confront threats to US troops stationed in Iraq such as Iran-backed militias.
“A repeal and a replacement should be simultaneous,” Mike McCaul of Texas, the top Republican on the Foreign Affairs Committee, argued before the vote.
“This feels like yet another political effort to undo one of [former president Donald Trump’s] boldest counter-terrorism successes: using the 2002 [authorisation] to remove Qassem Suleimani from the battlefield.”
Several Trump administration officials also implied the 2002 Iraq war authorisation could allow the president to take military action against Iran because of Tehran’s support for Iraqi Shiite militias.
Mr Biden responded to a more recent increase in attacks on US forces in February by striking two Iran-backed Iraqi militias stationed in Syria.
The Biden administration did not invoke the 2002 Iraq war authorisation to justify the Syria strike and instead argued it was legal under Article II of the constitution, which gives the president the right to use military force to defend US troops.
However, the Biden administration has not provided any public evidence that the Syria strike thwarted an imminent attack on American forces, prompting some pushback from within his own party.
The Senate Foreign Relations Committee will also consider similar legislation to repeal the 2002 Iraq war authorisation next week.
Senate Majority Leader Chuck Schumer endorsed the repeal on Wednesday, but Minority Leader Mitch McConnell came out against it on Thursday.
Republicans Rand Paul of Kentucky and Mike Lee of Utah have signed on to the Senate version of the repeal legislation.
Ms Lee and several other Democrats are also pushing to repeal the 2001 military authorisation, which multiple presidents have used as the legal basis for military operations in more than 40 countries against terrorist groups such as Al Qaeda and ISIS.
Repealing that authorisation would raise legal questions about the Biden administration’s ability to maintain a troop presence in Iraq and elsewhere.
And the White House has indicated it would not support a full repeal of the 2001 authorisation without a replacement.
Efforts in Congress to replace that authorisation with a more updated version ran into a standstill during the Obama administration amid disagreements over issues of scope, such as geographical limitations.
However, Republicans have expressed interest in bipartisan work to reform the Vietnam War-era War Powers Resolution as part of a broader bipartisan push in Congress to rein in the White House's expansive interpretation of the president's war power authorities.