Should the Parliament rather than the government decide if Australia returns to Iraq?
The rules on this are clear enough but factors unique to Iraq mean this is not as clear cut for all.
Those who answer yes to a parliamentary vote – the Greens, and independents like Andrew Wilkie – are the same ones who would also answer no to the primary question.
What they want is not so much a vote, as its anagrammatic variant, a veto.
In Australia, however, the power to embark on military action resides with the executive – the Prime Minister, the cabinet, and its national security committee.
The NSC has met multiple times recently on this very question and has, we are told, endorsed the first steps: to wit, humanitarian food and supply drops by C130 aircraft to beseiged Kurds, and a hand-over of weapons and ammunition to Kurdish Peshmerga forces "in coming days".
As one of the nation's foremost legal academics, the ANU's Don Rothwell, has pointed out, genuine question marks hang over the legal basis of an increasingly likely military campaign – not least arising from the absence of a functioning representative government in Baghdad.
But putting aside even these concerns for a moment, might there be a special case for a parliamentary discussion, if not a binding vote?
This, after all, is Iraq, a place where Western democracies so recently spent their entire reserves of domestic trust and credibility.
Just over a decade ago, governments including the US, Britain and Australia, bludgeoned their resepective polities and the broader international community with fabricated intelligence of weapons of mass destruction and therefore of an imminent threat.
The war was a disaster and the failed state it bequeathed is the very agar in which the virulent strain of hyper-violent Islam now raging in northern Iraq and Syria has grown.
Now, as then, the level of threat is being emphasised.
ASIO director-general David Irvine has noted that the campaign by the Islamic State, also known as ISIL, has drawn new adherents from the West, including Australia, in numbers which dwarf all the other bloody jihadist wars including Afghanistan, put together.
Some 60 Australians have joined ISIL fighters and another hundred or so Australians are active supporters and recruiters, Irvine says.
US Defence Secretary Chuck Hagel has described ISIL as "an imminent threat to every interest we have, whether it's in Iraq or anywhere else".
And Tony Abbott has repeatedly referred to beheadings, crucifixions and mass killings, warning we don't go looking for these conflicts, they come looking for us.
Persuasive as the humanitarian and strategic arguments are, erstwhile eager members of the coalition of the willing must recognise the betrayal of the last Iraq adventure.
Where once there was trust, now resides cynicism.
There are sound political reasons to oppose a parliamentary vote and several impracticalities mean it is not going to happen. But the WMD debacle is a key reason why many Australians believe it should.
