Will we kill civilians in an effort to save them?

The humanitarian intervention problem is that the following two propositions are both equally true.

First, there is a moral imperative to prevent humanitarian tragedies.  Any notion of state sovereignty has no force when that state is murdering its own citizens.  And "it's none of my business" is not an appropriate response to foreign atrocities.

But second, military interventionism is unlikely to be effective at anything more than achieving immediate, short-term goals.  It is certain to have unanticipated and unintended consequences.

At best the results of intervention will be unpredictable.  Preventing tragedies in one time and place may indirectly contribute to tragedies in another time and place.  At worst we end up killing civilians in an effort to save them.

Neither of these two propositions ought to be controversial.  The former is an obvious moral truth.  The latter has unfortunately been demonstrated over and over again.

It's easy to think of instances where military intervention has been ineffective or counterproductive.  It's less easy to recall examples of clear success.  The successful reconstruction of Germany and Japan after World War II seem more like mysterious outliers than models to emulate.

Despite this sad record, there is an emerging doctrine in international law and relations called the "responsibility to protect".  The idea is that while states have the ultimate responsibility to look after their citizens, those that fail to do so are liable for foreign intervention — from gentle diplomatic suasion right up to military action.

Known informally as "R2P", this doctrine was first acted upon in 2011 with the military intervention in Libya.

Few dictators deserved to be overthrown more than Muammar Gaddafi.  But three years later Libya is in chaos.  Just last month Human Rights Watch was reporting war crimes in the ongoing battle for control of Tripoli.  There are a quarter of a million militia fighters in Libya.

So unless R2P advocates only care about the very short term, it is fantasy to describe the Libyan intervention as a success.

Yes, it is possible that Western military action prevented something worse.  But that counterfactual is impossible to test.  The measure of humanitarian intervention can't be simply whether we can defeat third world dictators in battle.  We can.  What happens after the initial intervention matters too.

I'm sure the legal validity of R2P has been carefully worked out by international lawyers and scholars.  But as a guide for policy, it is a triumph of hope over experience.

It is sometimes claimed that the 2003 invasion of Iraq would have been a clear success if Barack Obama hadn't withdrawn troops in 2011.  Like Gaddafi, Saddam Hussein deserved his fate.  Perhaps if coalition troops had stayed then we wouldn't be facing the Islamic State problem now.  (See, for instance, this recent piece in the Washington Post.)

However, if the success of the 2003 Iraq war was really dependent on a never-ending military commitment, then it was hopeless from day one.  Domestic political constraints make permanent occupation impossible.  The public tolerance for casualties and deficits is finite.  Eventually voters turn against war.  This domestic reality has to be factored into intervention planning.

And yet ... it is simply impossible to watch overseas tragedy unfold without wanting to prevent it.  One 2010 book put this way:

Even those who are deeply suspicious of armed humanitarian intervention and deeply sceptical about its prospects of success may still admit that it might, in theory, be justified when a humanitarian crisis is sufficiently serious.

That intervention has failed in the past does not mean it inevitably fails in the future.  No doubt there are some Libyans alive because of Western action.

But what's not acceptable is the "it's the thought that counts" school of humanitarian intervention which washes its hands of long-term consequences in order to bray about quick military victories and our altruism-by-force.

Take, for instance, this Guardian piece after the Libyan intervention:  "No large-scale military intervention ever comes free of moral hazard."

Or this one by the former US State Department official Anne-Marie Slaughter, proclaiming the moral goodness of intervention and Western values and all that, then casually admitting at the end that "Libya could disintegrate into tribal conflict or Islamist insurgency, or split apart or lurch from one strongman to another".

Overseas atrocities present a genuine and tragic dilemma.  The case for protecting civilians against IS is unimpeachable.

But Tony Abbott told ABC radio yesterday that he could not "promise perfect success".  This is not a good sign.  And the mission's goals are already hopelessly confused.

Attorney-General George Brandis says IS is an "existential threat" for Australia.  Yet, on the other hand, we're also being told what's planned is "a humanitarian operation to protect millions of people in Iraq from the murderous rage of the ISIL movement".

So which is it?  Are we at war to defend Australia or to protect Iraqis?  The distinction isn't minor.  Is our goal to contain the threat or to destroy it?

Contrary to what the Prime Minister has said, fighting IS is hardly a "specific and clear objective".  It seems like the exact opposite:  vague and open-ended.  Maybe we'll defeat IS.  Or maybe, in Obama's words, we'll just "degrade" it.

The truth is of course we are only returning to Iraq as part of an American coalition.  That the mission is unclear is a reflection on the Obama administration rather than the Abbott Government.

Either way, the question that policymakers have to confront is not whether we have a responsibility to protect Iraqis and Kurds from the IS menace.  The real question is whether we are capable of doing so.