There’s no need to believe what Russia says — that the United States has agreed to let 9,000 Daesh (the self-proclaimed Islamic State of Iraq and the Levant) terrorists to flee Mosul and go and fight President Bashar Al Assad in Syria. But the story “reported” on Wednesday by Russia Today (on the basis of a single anonymous source) does capture a strategic truth in the run-up to the attack on Daesh-controlled city in Iraq: The terrorists have good reason to flee — and the Iraqis and the US have strategic reasons to let them.
The battle to retake Mosul has been a long time coming. Daesh occupied the city in June 2014, without encountering much in the way of Iraqi military resistance. Mosul was the biggest and most important city to fall into the hands of Daesh. Before Daesh arrived on the scene, the city had a population of roughly two million, making it Iraq’s third most populous city. (Since then, at least half have fled or been expelled or killed, including essentially all the ethnic and religious minorities such as Kurds, Turkmen, Assyrian Christians and Yazidis.)
With Mosul, Daesh controlled a significant portion of Iraq. The Baghdad government couldn’t allow that indefinitely without appearing to give up on functioning as a sovereign state.
Yet, Baghdad took its time. First, it had to retake Ramadi, which didn’t fall until February. That required the use of militias backed by Iran, which Iraqi Prime Minister Haider Al Abadi ideally doesn’t want to repeat. Al Abadi has been worried about the political cost of a failed assault by Iraqi regular troops. And the US, which will have to support the attack from the air and with advisers on the ground, hasn’t wanted to press the timing too hard. There’s little political advantage to be gained from a major conflict in Iraq during the election season. And there’s plenty to lose if the attack falters.
Nevertheless, the first deployments of Iraqi troops near Mosul began in the spring. A slow encirclement has been proceeding apace. And a full-on push is now assumed by all to be imminent.
That leads to the question: To what extent will Daesh stand and fight?
No one doubts that there will be some resistance and the Pentagon says the defence includes trenches and booby traps.
But as far back as July, the Iraqi defence minister had claimed that militant leaders and fighters were leaving the city. This report probably had some truth to it. Recent reports from inside the city say that most non-Arab and foreign fighters have left.
The logic of tactical retreat is strong for Daesh. Its ideological predecessors in the Iraqi insurgency stood and fought the US in the second battle of Fallujah in 2004 — and were resoundingly defeated, at significant cost in manpower. Perhaps 1,500 insurgents were killed and another 1,500 captured.
The lesson for Daesh is not to fight an unwinnable battle. Instead, the best strategy is to act like a classic insurgent force: Offer only token resistance at the advance of regular troops, and return if and when the Iraqis seem like they can’t defend or control Mosul. It’s far from certain that the Iraqi state can effectively govern Mosul or control potential ethnic conflict.
There’s some cost for the Daesh in giving up territory, simply because its legitimacy has derived from controlling so much of it. But because the group still controls plenty of territory in Syria, that’s a cost it can probably bear.
As for the Iraqis and the Americans, they’d like nothing better than to take Mosul without firing a shot, the way Daesh did in 2014. No one is really sure how well the Iraqi army will operate under fire; its record isn’t very impressive. US air strikes will inevitably kill civilians and devastate the city’s infrastructure, which will make the task of rebuilding harder, which in turn will make it even harder for the Iraqi government to establish control.
Also, no one knows exactly how many Daesh terrorists are in the city now. One Kurdish estimate from September put the number at 20,000. That sounds high, but US estimates of 3,000 to 4,500 may be optimistically low.
So if Daesh fighters want to leave Mosul now, it’s in Iraqi and American interests to let them go. Killing militants as they retreat towards the Syrian border may backfire by forcing Daesh terrorists to stay on and fight in Mosul.
This brings us back to the Russian assessment that the fighters will be allowed to go to Syria to fight Al Assad — and his Russian allies.
The US and Iraq have, of course, no interest in seeing a Daesh offensive against Al Assad. The administration of US President Barack Obama is not going to ally itself with Daesh — the ideological source of terror attacks in US and Europe. But there is a certain zero-sum effect to the movement of Daesh terrorists. In practical terms, any fighter who is able to make it to Syria will in fact strengthen Daesh against its opponents, including Al Assad.
In the long run, the answer for the US is to reduce the so-called Caliphate’s geographic footprint. Retaking Mosul will be part of that process. But victory over Daesh will ultimately require solving the question of Syria. And that remains a bridge too far for US policy, even though Russian President Vladimir Putin has a very clear idea of the result he wants.
Noah Feldman is a Bloomberg View columnist.