The groups in question had different agendas. On the more moderate side of the spectrum was the Islamic Army, which post-2011 U.S. withdrawal demobilized and set up the Sunni Popular Movement, in a bid to push for a Sunni federal region in Iraq. In contrast Jaish al-Mujahideen had always struck a nationalist, Salafi and anti-Shi’a rejectionist tone towards the post-2003 order. But as you note, most of these brands only really re-emerged with active advertisement of militant activity and evidence of a presence on the ground in 2013-2014, and the key early example of coordination with IS came in the fall of Fallujah at the beginning of 2014, which was often described inaccurately at the time as having come under IS control. Coordination also occurred in the summer offensive in the captures of cities in the north of the country including Mosul and Tikrit.The main reason for coordination was undoubtedly hope on the part of these groups that they could carve out their own spheres of influence without being subjugated by IS. But quite predictably, the opposite of what they expected took place, over varying degrees of time. The other insurgent factions in Fallujah and the wider area held out for some time in the face of IS, which really became dominant in the city by May-June 2014, and defeated Jaish al-Mujahideen in a confrontation in al-Karma (al-Garma) to the east of Fallujah city in late August 2014, forcing it to withdraw from the town. As a result of these developments, IS created its own “Fallujah Province” in September 2014. In other areas of Iraq, such as Mosul, which fell in June 2014, it took much less time for IS to gain the upper hand, within a month or so, reflecting IS’ stronger position with its gains in Syria and its deep entrenchment in Mosul. More generally, a trend that very quickly emerged over the summer of 2014 was IS’ consolidation of the cities, while other factions left for the countryside.Even so, things only continued to get worse for these groups, as members continued to give allegiance, were arrested or killed by IS, or simply fled and quit the field. The worst affected was Jamaat Ansar al-Islam, a jihadist group that had mainly been active in Ninawa and Kirkuk provinces and had set up a Syria branch in 2011. Jamaat Ansar al-Islam initially coordinated with IS in the offensives on Mosul and Tikrit but rapidly lost members to IS. Undoubtedly part of this trend was the result of the fact that Jamaat Ansar al-Islam has the same end goal of a Caliphate and since IS already declared itself to be the Caliphate, ideological incentive for defection exists.Thus, it is estimated from remnants of Jamaat Ansar al-Islam who did not defect that around 90% of members gave allegiance to IS by the end of August 2014, which IS then exploited to have senior defectors issue a statement in the name of the whole group in Iraq declaring its dissolution. Though rejected by those who controlled Jamaat Ansar al-Islam’s official Twitter account, the remnant faction is too small to have any real influence on the ground. As a result, Jamaat Ansar al-Islam can be considered a de facto defunct group in Iraq as IS has continued to hunt down the remnants with impunity, while its offshoot branch in Syria still survives primarily in Idlib and Aleppo governorates.
The other factions continued to claim operations but directed against the government, of small scale and little significance, and these attacks have gradually declined to virtually nothing. For example, it should be noted that the “General Military Council for Iraq’s Revolutionaries,” a faction serving as a front for both the Jaish Rijal al-Tariqa al-Naqshibandia and the 1920s Revolution Brigades, continued to claim targeting of Taji military base to the north of Baghdad, and with the new government offensives in al-Karma, it even claimed some fallen fighters. But now the group’s official page is merely issuing occasional official statements and reporting on government abuses.
The Islamic Army occasionally claimed fighting in the countryside of Salah ad-Din province- such as in the Yathrib district- but that too has now vanished. By the group’s own admission, coordination had initially existed with IS but it eventually stopped as problems predictably arose (e.g. the Islamic Army once had a presence in Baiji city, but members gave allegiance to IS or left the city).
So in short, Iraq’s insurgent factions beyond IS have descended into irrelevance. From the little data left, it is possible some of them are operating in some countryside areas and in and around Baghdad city where one can still escape the clutches of IS, but this has no real impact on the overall security situation. The current crisis greatly differs from the Iraq War of the mid 2000s in that the insurgency was much more diverse back then, and members of non-al-Qaeda/Islamic State of Iraq groups played an important part in forming the Sahwa movement in 2007. One might have hoped that the same process could be repeated now, but that is not the case.
For many months and even now it has been widely supposed that JRTN is an “alliance of convenience” with IS. However such a notion is greatly mistaken. Non-IS jihadis would often draw attention to prior coordination between JRTN and IS in a bid to show that IS is not a legitimate jihadist group at all but rather a Ba’athist group in jihadi guise, a notion that has also gained some currency in the media. Further I think the perceptions of an alliance between JRTN and IS were reinforced by claims originating from Atheel al-Nujaifi [governor of Ninewa] in the summer that IS was withdrawing from parts of Mosul and allowing JRTN to assume responsibility for management.It is more accurate to characterize relations as one where JRTN, like the other insurgent factions, also hoped to have its own sphere of influence, but proved itself unable to withstand IS. This is true even in areas where many analysts expected JRTN to be particularly strong such as Tikrit and the surrounding area.The true nature of the relationship between JRTN and IS is best determined by reading between the lines of its statements issued over the course of 2014 and into this year. Though JRTN did not denounce IS by name in its statements and sometimes absurdly blamed the government in Baghdad, it clearly distanced itself from IS’ genocidal targeting of the Yezidis, displacement of Christians from Mosul, as well as destruction of heritage sites in Mosul and elsewhere.As 2014 came to a close, JRTN claimed Western attempts at outreach in a bid to form a Sunni force to fight IS as a sign of desperation at the strength of JRTN. JRTN was actually the one becoming increasingly desperate. Though strongly denying any involvement in discussions over participation in the proposed National Guard or other initiatives suggesting dialogue with the government, JRTN turned to regional Arab states such as Jordan and Saudi Arabia. This was reflected in effusive praise for the latter, and a remarkable eulogy to the Jordanian pilot Muadh al-Kasasbeh who was burned alive [by IS]. JRTN went so far as to hail him as a “martyr” carrying out obligatory duties of defending the “holy sites of our Arab Islamic Ummah.” This JRTN alignment with regional Arab states including Saudi Arabia was also reflected in Izzat Ibrahim al-Duri’s last recorded speech that came out this month, which also marked a reversion to classic praise for Gamal Abdel Nasser as the hero of Arab nationalism with distancing from the “takfiri” thought of IS. Contrasting with JRTN’s alignments, the 1920s Revolution Brigades vociferously condemned Arab state participation in the coalition against IS on account of the airstrikes on Sunni areas of Iraq.
The present state of JRTN suggests that some members are still present in areas under IS control- such as Mosul- but have no influence and live underground, with some very minor safe havens also in the Kirkuk countryside. As such, JRTN cannot be seen as the force that can defeat IS. For the same reasons also I do not see Duri’s death as having a real impact on events in Iraq, even if confirmed (still no confirmation either way from JRTN, whose last statement was in praise of the Saudi-led coalition against Houthis in Yemen).
The current ideological basis for IS demands of allegiance from other groups is its presentation of itself as the Caliphate, which requires allegiance from the world’s Muslims and the dissolution of all other groups and other organizations. However, this does not mean that IS had not exhibited similar behavior in its prior manifestations. For example, IS’ predecessor organizations had a long standing dispute with Jamaat Ansar al-Islam in Iraq, sparking clashes on multiple occasions in Ninawa and Kirkuk governorates and mutual assassinations. The key here is that although both groups have the same ideology, Jamaat Ansar al-Islam only considers itself a mere group (jamaat), while IS’ predecessors in the forms of ISIS (Islamic State in Iraq and al-Sham) and ISI (Islamic State of Iraq) already considered themselves a state in some form, and therefore demanded allegiance. The tensions were such that Jamaat Ansar al-Islam appealed to no avail in 2013 to Ayman al-Zawahiri to restrain ISI on the grounds that it was his affiliate in Iraq.The main difference following the fall of Mosul was that what became IS was much stronger than its predecessor organizations, with contiguous territory spanning borders, claims to state governance that translated to reality on the ground and the assumption of Caliphate status. Hence, IS demands for allegiance could not be taken lightly, and what followed was the rapid demise of Jamaat Ansar al-Islam over the summer of 2014.
Unfortunately, the present evidence does not suggest meaningful shifts in the tribal dynamics against IS. The initiatives that have arisen have mostly helped to prevent IS from seizing more territory rather than taking territory from IS. The most notable case is the Kata’ib al-Hamza in western Anbar, taking its name after the initiative that arose among Albu Mahal tribesmen in al-Qa’im in 2005 against AQI. Kata’ib al-Hamza draws on locals not only in Haditha but also dissidents from the Albu Mahal tribe in al-Qa’im and other far western towns in Anbar that are currently IS strongholds (Rawa, Anah and Rutba). The group initially claimed to have connections in these strongholds to undermine IS, but that has not so far been borne out on the ground. The Kata’ib al-Hamza’s main function has been to help prevent IS from taking Haditha. Even so, local resistance can be overwhelmed, as was the case when IS took the town of Hit in Anbar last year.More generally, new tribal initiatives have been repeatedly announced in a bid to roll back IS in Anbar but these initiatives tend not to be anything groundbreaking but are rather the same tribesmen who have been working with the government all along since the fall of Fallujah in January 2014. The notion of a viable ‘third-way’ tribesmen who are both against the government and against IS is mistaken, and part of the problem is that IS has been able to divide members of some of the same tribes against each other, a tactic IS also employed in eastern Syria as it consolidated control.
I think for the sake of media stories there is a tendency to be hasty and proclaim “IS is winning/losing” according to the latest development. It is however fair to say that on aggregate IS has lost territory in Iraq since the summer of last year, having lost all major towns in Babil and Diyala provinces (though in the latter, IS activity persists despite claims the province has been completely cleared of IS), as well as the town of Tikrit. Meanwhile, the fighting fronts in Anbar and Salah ad-Din are at best proving to be only stalemates, and it is notable that very recently Abu Bakr al-Baghdadi issued a mobilization call in the Syrian provinces to reinforce these fronts. Despite these setbacks for IS in Iraq, the fact remains that in the strongholds they control like Mosul, Tel Afar and Fallujah, they face no meaningful local opposition that can undermine their rule, which would be the most effective way of rolling back the bulk of its holdings in Iraq.
In Syria, IS has mainly been trying to expand in southern Damascus province and in eastern Hama province, having announced new “provinces” in these areas. Elsewhere, the frontlines remain largely static. For example, in north Aleppo countryside, there has been no meaningful shift in positions either way since August 2014 when IS seized some northern border towns and villages including Dabiq, which plays an important part in IS apocalyptic discourse. Indeed, that particular frontline (which I visited in December 2014) remains remarkably quiet, with only occasional exchange of gunfire and mortar rounds. Partly this has to do with the vast efforts IS put into trying to take the Kurdish city of Kobani but ultimately failed in the face of hundreds of coalition airstrikes and limited Peshmerga ground intervention. Ultimately I think these developments very much vindicate the cautionary words of Joel Rayburn who has repeatedly affirmed that we should not think of IS as an unstoppable juggernaut. The group does not have the resources to launch intense offensives on every front. But even so, the same point applies to the Syrian territories it rules as to its Iraq holdings: there is a problematic lack of meaningful local opposition to undermine its rule; and in Syria, IS has much more of a claim to the trappings of a state than it does in Iraq (e.g. in Raqqa IS is able to provide electricity as a public service, not so in Mosul). So if we are going to see the collapse of IS in Syria, I think this is still years off at best.