Liberating Islamic State's capital is the easy part

“We will soon announce zero hour,” the leader of one US-backed rebel group claimed, “for the beginning of the battle of liberation from oppression and persecution”.

Yet the coalition will likely run into two big problems if they don’t anticipate and plan for what will happen on the day after the city falls. Taking a city – especially one that has been ruled by a terror group for any length of time – comes with all manner of frightening possibilities, including general mayhem, a humanitarian crisis and a brutal settling of scores at the hands of the liberators.

First, however, expect the fight to be long, bloody and dangerous. A significant ground force could be required to expel Islamic State fighters, who are heavily armed and well-dug in, and then free the city of 200,000 people.

Consider the devastation wrought on the Syrian-Turkish border town of Kobani. House-to-house combat was required to keep Islamic State from seizing control of it. In Tikrit, Ramadi and other cities in Iraq, the militants have shown themselves willing to booby-trap vast swaths of territory to stymie efforts by liberating forces.

So, who will free Raqqa?

The answer remains unclear because there doesn’t seem to be many interested in carrying out this difficult mission. It doesn’t look like the Kurds are spoiling to take the largely Arab city. The United States will not be sending in significant ground forces to do the job. Turkey seems disinclined to send its forces across the border to wage war, particularly given Ankara’s hostility to most Kurdish insurgents. The various groups that make up the Free Syrian Army are far too weak to take on Islamic State directly.

In addition, the coalition fighting against Islamic State is certainly not eager for Syrian President Bashar al-Assad and his Iranian backers to march back into the city.

So, in reality, there is no ground force being assembled to accomplish this goal.

But what if Islamic State is indeed expelled from the city, perhaps by some fighting force backed by allied air power and small groups of US Special Operations and CIA forces on the ground? At that point, perhaps Washington can replicate its 2001 success of pushing the Taleban out of Kabul.

As much as half the city could well be flattened in the battle. So once the shooting ends, any liberating military would quickly confront a significant infrastructure and refugee problem. This invariably would lead to the second big conundrum: the critical effort of providing an effective government.

Who would rule Raqqa the day after it is liberated? What would happen to all the displaced people fleeing to or from the city? Recall the city’s tribal elders welcomed the Free Syrian Army and other rebel groups a few years ago. But Islamic State pushed all the rebels out when they proved unable or unwilling to govern the city. It is uncertain if any of these political groups can provide the force necessary to keep Islamic State at bay while maintaining law and order in the city.

As for the outside groups, from the Kurds to the Turks, it could quickly shift from liberation to occupation. A few ugly turns of events could make Raqqa look a lot like Baghdad in 2005. There is already concern that a Kurdish force will take revenge for Islamic State’s cruelties in Kobani and elsewhere. Islamic State could also go underground and emerge later to set off car bombs and deploy suicide attackers to spread mayhem. Concrete blast walls would go up all over the city. Daily life would become difficult to manoeuvre.

If US decision-makers aren’t considering these potential problems systematically, failure could result. Rather than focusing on the adrenaline-pumping aspects of bombing runs or counting Islamic State casualties, the administration should be thinking about how to provide security, jobs and sanitation for the citizens of Raqqa. For without that, Washington would likely again create a situation ripe for chaos and anarchy.

More troubling, the citizens of Raqqa might begin to view Islamic State as better civic leaders – as has happened in other regions of Syria. That would be a headache for decades to come.

Without a large stabilising force and an effective system of government that restores some semblance of normal life, the coalition would likely fail to achieve its objectives of liberating Raqqa — or any major slice of Islamic State-held territory – for very long.

The partners must start focusing on what might happen the day after liberation long before that day arrives. The complicated drawn-out process of rebuilding a society won’t make headlines. But if Washington and its allies are serious about defeating Islamic State, they need to think about what happens the day after they retake the city.