While Prime Minister Tony Abbott and Opposition Leader Bill Shorten are in lockstep regarding Australia’s need for a military role in Iraq, it is not just the Greens and the dovish Left who have come out against a new wave of Western military intervention.

The Lowy Institute’s Sam Roggeveen, who initially supported the 2003 Iraq War, last week called for a statement of Australia’s intentions in Iraq and an honest assessment of the threat posed by the Islamic State:

“Sometimes it feels as if the post 9/11 period has never happened, because we keep making the same mistakes: we hype the threat, terrorise ourselves, and over-react in ways that only strengthen those we are fighting. Let’s take a deep, deep breath before starting on the same road again.”

Andrew Bacevich, a professor of international relations at Boston University, wrote in conservative magazine The Spectator that the best course of action for the West is “simply to butt out”:

“The United States and its European allies do not possess the wit nor the will nor the might to fix whatever it is that ails much of the Islamic world. This is the principal lesson that the long Iraq war has to teach,” Bacevich wrote.

Bacevich retired with the rank of colonel from the United States Army before gaining a PhD in American Diplomatic History from Princeton, and was a vocal critic of the Iraq War. His son, also an army officer, died fighting in Iraq in 2007.

Allan Behm, former head of the International Policy and Strategy Divisions in the Department of Defence, suggests a more nuanced approach to foreign intervention:

“The question that Australian governments must ask themselves is whether support for US-initiated and US-led military action serves either the interests of the states where force is to be used, or those of Australia,” Behm said.

Behm had previously supported the decision to send Australian troops to Iraq to protect the Australian Embassy.

Age columnist and professor of strategic studies at ANU Hugh White warns the West must be willing to use massive resources if it wants to change the region’s political order:

“As we saw in Libya, campaigns of air strikes can affect what happens on the battlefield, but they confer no control over the political consequences of victory or defeat. Only troops on the ground can do that, and only in immense numbers. So only those willing to commit huge ground forces have any hope of being able to shape the outcome. Anyone else would be better staying away.”

White was critical of John Howard’s decision to send troops to Iraq in 2003 but later supported the decision to send in extra troops in 2005, highlighting Australia’s “moral obligation” to ensure political stability.

And former Liberal adviser, editor of the Spectator Australia and IPA regular Tom Switzer penned an op-ed for the Australian Financial Review quoting none other than Greens leader Christine Milne:

” … remember the adage ‘the road to hell is paved with good intentions’. We learnt that lesson at great cost during the last Iraq war. That is what, in essence, Greens leader Christine Milne means when she asks: ‘If we’re going to start, where is it going to end?’ She has been denounced as an appeaser and coward. But it is precisely the question our Parliament should be raising in coming weeks.”

The government and opposition have shut down debate on the issue in Parliament, but outside Canberra’s halls of power plenty of people from the Left and Right are urging caution.