The imperative is to do something - 'do something even if it's stupid', as has been said.
As airstrikes continue, IS will naturally become more skilled at hiding amongst the civilian population. Bombs will inevitably kill civilians. International support for the action will turn.
What is our exit strategy? If we don't know what we want to achieve, then it's impossible to know when the job is done and it's time to go.
So, there is no exit strategy. Should we be involved because IS is a threat to NZ? John Key has said "IS will rain carnage on the world".
No, IS is not threatening the world. They are a brutish, nasty group that uses terror and atrocities as a weapon to dominate parts of two countries.
We should remember Tony Blair and his cabinet in 2002, who said that Iraq posed "an imminent threat to Britain". That's laughable today. We should not similarly exaggerate IS to justify military action.
IS is sophisticated. It is reaching out to Muslims around the world, asking them to take up arms. We need be mindful about fringe members of our peaceful Muslim community being radicalised. We should understand that a deployment could create greater insecurity in NZ.
The UK's role in the Iraq war increased the radicalisation of young Muslims there, according to a study by the Royal United Services Institute: "Far from reducing international terrorism ... the 2003 invasion [of Iraq] had the effect of promoting it."
The politics of fear should never justify a deployment that simply doesn't stack up. Do we need to be there to help our mates, as John Key is saying?
The Iraq War began within the Bush Administration for ideological reasons. The US and UK led the operation with Australia playing a military role.
We were different. We chose to stay out.
Colin Powell said to President Bush prior to the invasion of Iraq: 'You will own all their hopes, aspirations, and problems. You'll own it all.' Privately he said: 'You break it, you own it.'
The US is owning what has failed in Iraq. But that responsibility doesn't logically flow to us.
The Middle East does follow one law: the law of unintended consequences. The region is hugely complex with multiple agendas. We are deluding ourselves to believe we are going to make a measurable difference.
Western interventions, historically, have commonly ended in disaster. If the US knew 10 years ago what Iraq would look like today, would it still have invaded?
We have no idea of the future consequences. Neutralising IS, for example, will strengthen its enemy, Syrian President Assad -- a man who thinks little of gassing his own people. Thanks to him, nearly 200,000 Syrians have died in the past 3 years.
And on the Arab streets, there is growing hostility to more Western interference.
What should we do then? New Zealand has always been a good global citizen. We have put our people in harm's way where we felt it was right. We all detest the tactics and agenda if IS. But the strategy to deal with IS should be broader than military action.
Economically IS is most vulnerable. IS oil shipments through Turkey should be shut down, its arms supplies cut off. We should use our place on the Security Council to organise UN resolutions to achieve a truly international response against the abuses of IS. We should continue - and increase - our humanitarian assistance.
Iraq is not the only place facing threat. Can we contribute elsewhere - to stopping the spread of Ebola?
As ever, Kiwis are ready to do the right thing. But the case for military action has not been made on Iraq. And it should not be a decision rushed through for a G20 summit.
David Shearer is the Labour MP for the electorate of Mt Albert and a former United Nations worker.
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