The US Senate is this week set to vote to repeal two decades-old war authorisations that provided the legal cover for wars against Iraq.
The so-called Authorisations for the Use of Military Force were passed in 1991 after Iraq invaded Kuwait and in 2002 ahead of the US-led invasion of Iraq the following year.
What is an AUMF?
Under the US Constitution, Congress — not the president — has the right to declare war. But to allow a president to respond to a threat, the Senate and House of Representatives can pass an AUMF.
The two that may be repealed this year have been labelled “zombie” authorisations because they never expire but their original purpose no longer applies.
Critics say the AUMFs should be repealed because Iraq is not a US adversary and because they could pave the way for future destabilising military action that has little to do with the original intent of the authorisations.
Some criticised Republican then-president Donald Trump's use of the 2002 Iraq AUMF for the 2020 killing of senior Iranian military commander Qassem Soleimani, who was in Iraq but whose targeting was not connected to the earlier war.
What about the 'War on Terror'?
Members of Congress are not — for now — targeting a third AUMF, which passed days after the September 11, 2001, attacks. The measure authorised then-president George W Bush and presidents since then to target Al Qaeda.
Because that AUMF also does not expire and was not limited by geography, it has been used to justify military action around the globe. Lawmakers say the campaign against militant violence is too important to repeal the 2001 authorisation before a replacement is written.
Will the repeal be passed this time?
Congress has tried and failed to repeal AUMFs repeatedly over the past 10 years.
Backers say things are different this time, partly because it has been 20 years since the last Iraq war began, and because Democratic President Joe Biden has said he supports the repeal and does not believe it will harm national security.
The measure has both Democratic and Republican co-sponsors in both the Senate and House. It is expected to easily pass the Democratic-led Senate.
Its fate in the Republican-led House is less clear, given that support for AUMF repeals in the past has been much stronger among Democrats than Republicans.
Republican House Speaker Kevin McCarthy said this month there was a strong chance the House would pass a bill.
