Iraq faces an existential crisis. Daesh (the self-proclaimed Islamic State of Iraq and the Levant) controls almost a third of Iraq, and most of its Sunni population. When people ask me whether I think Iraq will break up in the future, I tell them that it already has. The question is whether the international community is prepared to allow the status quo to remain or whether we intend to roll back the gains of Daesh. And if we intend to roll back those gains, what role should the US military play?

The role of the US should be to support and strengthen the Iraqi military. The US is the only force capable of providing the support Iraq needs to fight the existential threat of Daesh. And US support should be delivered directly to the Iraqi military, which is still the most powerful force available to fight Daesh. Indeed, we should not underestimate the Iraqi army’s ability to fight, if it has the right support. For more than two years, the Iraqi Army’s Seventh Division (almost entirely Sunni) and its army and police special forces have been fighting in Anbar, but they are exhausted. The 450 extra trainers announced last week (two thirds of whom will be in support roles, not actually training) is a start, but is not enough.

Further, instead of underestimating the enemy, we need to accept that Daesh is actually a powerful adversary, requiring a committed response. Daesh has enjoyed battlefield success against not only the Iraqi Army, but also the Free Syrian Army, Al Qaida’s franchise Jabhat Al Nusra, the Syrian Army and of course the Kurdish Peshmerga. And we need to remember that Daesh is the direct successor of Al Qaida in Iraq (AQI), which killed and wounded so many US soldiers and Marines. Indeed, the US Surge and Sunni Awakening of 2007 did not defeat AQI: Although suppressed, AQI was never entirely defeated, it simply went into operational hibernation, only to re-emerge in late 2009 with spectacular bombings in central Baghdad that reduced several government ministries to rubble and killed hundreds of civil servants.

Since Daesh’s lightning sweep across northern and western Iraq a year ago, a combination of Iraqi army units (including the small but highly effective special forces), the popular mobilisation (Al Hashd Al Shaabi) and US airstrikes have held the line. The Hashd has proved able to garrison cities like Samarra and prevent further encroachment by Daesh. However, the Hashd was not able to dislodge Daesh from Tikrit, which was retaken when Daesh withdrew in the face of US-led airstrikes. And the ill-considered Iraqi offensive in Anbar province in early April, which followed the Daesh withdrawal from Tikrit, demonstrated the Iraqi army’s limited offensive capabilities.

Even before May 17, when Daesh finally broke the last government resistance in Ramadi with more than 20 car and truck bombs (some as powerful as the Oklahoma City bombing) serious gaps in Iraqi military capabilities had become evident. Command and Control, communications, joint operations, intelligence, air support and perhaps most importantly, logistics are capabilities with which the Iraqi military still struggles. My own experience, and that of my colleagues, was that the Iraqi military was not yet a mature force when the US withdrew. We spent years building a professional and well-equipped military, but we left just before it was ready.

Iraq needs increased US military assistance in certain essential areas. Even with the planned delivery of Iraq’s F-16s this year, the Iraqi Air Force is not yet ready to provide the amount of air support required. But US and Coalition aircraft need US personnel alongside Iraqi forces in the field to target airstrikes. Iraq’s military logistics system is still basic. The US needs to again provide the logistics support the Iraqi security forces require; this is not a small undertaking, but it is essential. US special forces can also provide the type of highly effective direct action capability that we saw in the Osama Bin Laden raid in 2011 or against Abu Sayyaf in Syria last month. Likewise, the US should help the Iraqis tie together their various security forces via restructured command and control. Furthermore, many more US trainers are needed and the trainers need to accompany Iraq forces into the field, for training does not just happen on a base. And the US military can assume again the role of honest broker it previously held. It is no coincidence that Sunni tribal leaders and politicians, such as Sahwa leader Ahmad Abu Risha, Anbar provincial council chairman Sabah Karhout, Anbar governor Suhaib Al Rawi and speaker of parliament Salim Jibouri, have been travelling to the US to request for assistance, it is because they see the US as the only neutral arbiter — and they will fight if they believe they have US military support.

America does not want to lose any more young men and women in Iraq. And there are also many in the international community who would be happy to see Iran take a more active role in stabilising the country. But the rapid advance of Daesh towards Erbil and Baghdad in August 2014, which was only halted by US air power, shows Iraq cannot stand by itself. Likewise, the inability of the Iranian-supported Hashd to retake territory from Daesh, and the recent defeats of Hezbollah and Iranian forces in Syria, expose the limits of the Iranian military and paramilitary forces against Daesh.

In the last decade, only the US military has enjoyed any level of success against Daesh’s predecessor — AQI. Moreover, the US military built the Iraqi military and knows it inside and out. And Iraq knows full well that the US harbours no territorial ambitions, nor does it want an occupation. The US faithfully left in 2011 according to the timetable outlined by former US president George W. Bush and former Iraqi prime minister Nouri Al Maliki. It will do so again, but hopefully this time once the job is done.

For the opposing view in the Gulf News Debate, see: Further meddling can only make matters worse, by Abdel Bari Atwan

Dr Norman Ricklefs was senior adviser to the Secretary General of the Iraqi Ministry of Defence and to the minister of interior. He now heads the private sector consultancy, the Iraq Advisory Group.