An excerpt from, "What is hiding behind Islamic State" by Nadim Shehadi, Chatham House, December 2014:
One element is the General Military Council for Iraqi Revolutionaries, former Ba’ath Party officers from Saddam Hussein’s disbanded army with over thirty years of experience ruling the land. Many have been in hiding or in exile, given sanctuary and support by the Syrian regime.
Another important element is the Army of the Men of the Naqshbandi Order, a Sufi order which is powerful in the region and with connections that are not well understood. They include senior members of the AK party of the Turkish president, Recep Tayyip Erdogan, and Muslim clergy in Syria and Lebanon.
The third element are Sunni tribes in the western provinces of Iraq who are disaffected with the policies of Shia hegemony of the former prime minister, Nouri al Maliki, and bitter at being abandoned by the Americans with whom they collaborated to get rid of Al-Qaeda in Iraq during the ‘Surge’ in 2007-08. Some of the reported massacres in western Iraq, brutal as they are, may have more to do with Ba’ath-style re-establishment of control in these provinces than with what we think of as the jihadism of Islamic State.
These disaffected Sunnis are the real forces hiding inside the barn. They have local support and connections that may explain the speed with which they took over territory; they may be led by Izzat Ibrahim al-Douri, second in command in Saddam’s regime and the King of Spades in the US’s deck of cards. He is described as the hidden sheikh of the Naqshbandi order.
The fourth element – the one everyone can see – is composed of the remnants of Al Qaeda in Iraq most of whom have been released or escaped from Syrian and Iraqi jails. These had played an important role in destabilizing Iraq in 2006/7, a role facilitated by the Syrian regime.
This element, joined by foreign fighters, is the barn inside which the rest of that toxic mixture of disaffected groups is hidden. The purported Salafi Islamist creed of Islamic State is incompatible with the other elements within it: the secular nationalism of the Ba’athists is anathema to the so-called caliphate proclaimed by Islamic State; Sufis such as the Naqshbandis are considered heretics and apostates; and tribal leaders are always wary of losing followers to cults.