By now many will have seen the pictures. Pick-up trucks driving in convoy, men with black scarves wrapped tight around their faces. Assault rifles held aloft. Behind them the black flag of the Islamic State of Iraq and the Levant flies high.
The ISIL has hit the headlines in a big way over the last few days. But what is ISIL? Its definition is far more complicated than its public image suggests.
ISIL has become a brand name, a name to rally around for those looking to fight, according to some. Sa'ad Ma'an is the spokesman for Iraq's Interior Ministry. In April we discussed his government's campaign against ISIL that continues to this day. I asked him who they were. "They are a media creation, a creation for terrorists to hide behind," he replied.
Increasingly many believe this to be the case. In Iraq a man called Ezzat Ibrahim al-Douri continues to be on the run. In the run up to the invasion of Iraq in 2003 US forces distributed a pack of playing cards with Iraq's most wanted on them to its soldiers. Douri was the King of Clubs. He is the only senior Saddam loyalist still on the run.
He's an old man now, but he has become a spiritual figurehead for a powerful militia group called the Naqshbandi, a group that clings to a Baathist ideology and often mix it with Islamic sufi ideology. They're hardened fighters led by former Saddam soldiers and have trained a younger generation to fight.
As former military men, they know Iraq well. For many it was them in conjunction with ISIL that were able to take Mosul. Over the last few days I have spoken to several people inside Mosul who have told me that overwhelmingly a majority of the fighters under the ISIL banner are Iraqi.
While that may not come as a shock - we are in Iraq after all - it is telling. Mosul by all accounts is peaceful. The fighters have cleared checkposts, removed barriers and blast walls. They encouraged people to come out onto the streets. One of my contacts told me: "They treat us with respect. I fear them, but they haven't harmed us."
ISIL fighters have also asked shops and businesses to open and for people to go back to work.
Such close interaction with the fighters has lead the people in Mosul I have contacted to suggest that they are more moderate than many have been led to believe.
Then on Thursday, news began to leak that differences had occurred between the factions of ISIL and that the Naqshbandi were pushing for a move to Baghdad for "regime change".
That puts them at odds with ISIL's goals of establishing an Islamic caliphate across Iraq and Syria. Naqshbandi would, if there public statements are to be believed, be happy overthrowing the Maliki government and taking over Iraq.
ISIL in many ways have become powerful due to their bold attacks and their leader, Abu Bakr al-Baghdadi, positioning himself as the next Osama bin Laden. His public pronouncements even suggest he wants to take on the leadership of al-Qeada.
War does make strange bedfellows. ISIL certainly isn't the homogeneous group we have seen over the last year. The more victories it gets, the more groups will rally to its banner. While that might help militarily, sharp differences in ideology may not keep all the groups together in the long term.
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