The insurgent situation today in Iraq is much different then before. It is much more homogenous. Serious analysts estimate that ISIS is responsible for anywhere from 75-90% of all attacks in Iraq. Some groups almost completely disappeared. The Islamic Army is an example. This week was the first time in 2-3 years that it claimed that it carried out an independent operation. 1920 Brigades, Hamas Iraq, etc. those groups are trying to make a comeback but were basically dead by 2011. ISIS by far is the largest, most well armed and effective group. It also controls large swaths of Syria which it administers like a state. After ISIS Ansar al-Sunna is likely the second biggest. It too sent fighters to Syria. It is closer to Al Qaeda central and a rival of ISIS. The Baathist Naqshibandi (JRTN) is third. It has cooperated with ISIS before but is really in its shadow as the constant attacks by ISIS upon its members over the last few months show. All these groups are trying to expand into the security vacuum but to say that they can make any serious challenge to ISIS is not possible right now. They are just very small compared to the Islamic State.