In 2003, Coalition forces decisively destroyed the Iraqi Army and toppled Saddam Hussein. The military mission had been accomplished, but what was left?

While the decisive phase of Operation Iraqi Freedom ^[1] (OIF) was relatively well planned and executed, insufficient consideration was given to arguably the most important phase—stabilising the environment after the shooting stopped. The key lesson for campaign planners was the need to articulate a unified end state—a clear and agreed vision of what peace should look like.

Fast forward to 2014 when another US-led coalition entered Iraq, this time in response to a request from the Iraqi Government after the so-called Islamic State (Daesh) captured a number of Iraqi cities, and gained effective control over a significant part of Iraq’s territory. Combined Joint Task Force – Operation Inherent Resolve (CJTF-OIR) ^[2] was established to help Iraq defeat Daesh. With a limited mandate, the coalition primarily focused on training, and advising and assisting the Iraqi Security Forces (ISF), as well as providing air support.

Iraq is now a coalition partner, fighting another war on its own soil against an insurgency and terrorist group. In the past 12 months, the ISF has—with considerable support—made slow but significant progress recapturing Iraqi sovereign territory and militarily defeating Daesh.

With Daesh now on the back foot in Iraq, a military victory is again likely. But have we learned the lessons of 2003? As with Coalition forces then, the task on the battlefield won’t be as challenging as ensuring long-term peace and stability when the fighting ends. And the consequences are serious: a failure to prepare to establish peace and stability in Iraq will have significant implications for the global terrorist threat.

For Australia and the broader international community, Iraq remains critical in the fight against terrorism. An unstable Middle East region, characterised by chaos, violence and uncertainty, provides a prime breeding ground and focus point for violent extremism, and an ideal training ground for terrorists. Iraq matters to our counterterrorism efforts because many of those terrorists, who complete their apprenticeships in Iraq, will advocate attacks on Western targets through remote recruitment, support and direction, or undertake attacks themselves.

In defining the peace we seek, it’s first necessary to understand the complex environment of Iraq. One of the Iraqi government’s main challenges is that it isn’t just the ISF fighting Daesh. The fighting force is made up of a large number of internal and external actors, including numerous Shia militia groups, Sunni tribal fighters, Kurdish Peshmerga and Iranian Revolutionary Guard Quds Forces.

While at face value that represents an increased fighting force ratio, the question is why are all those groups doing the Iraqi government’s fighting for them?

The most obvious reason is to protect Iraq. But looking deeper, each of those groups has its own agenda and interest in Iraq’s future.  They have competing visions for Iraq’s future which stand in contrast to Baghdad’s—and indeed Canberra’s—envisaged end state.

The political landscape in Baghdad is becoming increasingly murky. It is a momentous challenge for the Iraqi Government to reconcile Sunni, Shia and Kurdish grievances whilst fighting a war and also trying to keep Iran at arm’s length.

When Daesh is defeated, what will become of the armed militia? Will they pose a new internal security threat for the Iraqi Government or will they be absorbed within the ISF? The cost of both options would be enormous.

What of Shia Iran and its role? How about the West? What’s the future for defeated Daesh fighters who tactically withdraw and attempt to re-integrate within Iraqi society?

While there are no clear answers yet to those questions, one thing is certain: for years to come, Iraq’s internal environment will be dominated by a highly diverse and complex demographic comprised of those disparate factions, hampered by ongoing political, ethnic and sectarian tensions in a hotly contested and dynamic region.

To illustrate the point, as a combat team commander in Iraq in 2007, the primary threat to my force was the army of Shia Cleric, Muqtada al-Sadr’s, Jaysh al-Mahdi (JAM) ^[3]. JAM’s mission was to undermine the will of coalition forces, primarily through using improvised explosive devices (IED). From January 2007 to June 2008, JAM was responsible for more than 1,500 IED attacks ^[3] against coalition forces.

Eight years on, as the commanding officer of the first Australian and New Zealand Training Team of Task Group TAJI ^[4] in 2015, I was bemused to learn that JAM had rebranded itself as the ‘Peace Brigade’, Saraya al-Salam. More puzzling is the fact that this Shia militia group is now a coalition partner, on our side, fighting Daesh. This Shia militia group tolerates the coalition presence for now, while we share a common enemy in the Sunni Daesh, but there will likely be a tipping point in the future where they switch sides and again target coalition forces.

There are no easy solutions to those security challenges, and no guarantees, but Iraq is worth fighting for because the risks associated with inaction are too great. While there’s instability and conflict, Iraq will remain a breeding ground for violent extremism and a training area for foreign fighters, some of whom will return to their countries of origin.

For this reason, Western governments need to better collaborate with their partners in the Middle East to develop a clear understanding of what the peace should look like, and harness all elements of international power to design and execute a coherent strategy for the region.

Likewise, Australia must consider Iraq an essential piece within a fully-integrated, whole-of-government counterterrorism strategic plan ^[5], particularly as Daesh looks to extend its reach to Southeast Asia ^[6].