Correction, 20/4/2005: An earlier version of this text said that General John Allen is in charge of the coalition air war against ISIL. This was incorrect. The air war is coordinated by the US military. 

Retired US General John Allen, the former US commander of NATO forces in Afghanistan, is running the biggest campaign of his career.

We have to deglamourise Daesh. We have to explode this myth of inevitability of the caliphate .... When we have defeated the idea of Daesh, then we have truly defeated Daesh. We are going to defeat Daesh militarily ... but the attractiveness of Daesh and the allure of that message, when we can defeat that, that will ultimately spell the end of this movement.

General John Allen

Allen is the special envoy in charge of coordinating the global coalition against the Islamic State in Iraq and the Levant, or ISIL.

He's not in charge of the coalition's air war - that is the job of the US military.

Allen's brief is much, much larger: he is trying to starve ISIL of its cash; destroy its PR machine, which has drawn thousands of fighters from around the world to Syria and Iraq; and help the many tens of thousands of people terrorised and displaced by the group.

But the mission is highly complicated - more than 60 countries are involved.

Old political tensions are aggravated by what Allen says is the need for cooperation.

And defeating ISIL, says the former commander of US troops in the Middle East, could take years.

But Allen believes that the campaign will be successful "Daesh has become a proto-state … it has even attempted to have its own currency … when it transitioned to becoming a proto-state it created its own vulnerabilities. We can sense those vulnerabilities ... and a combination of pressures on those vulnerabilities will ultimately begin to degrade Daesh and will ultimately defeat it."

General John Allen describes the shape of the campaign against ISIL, the challenges, and the early successes, as he talks to Al Jazeera.

Source: Al Jazeera