When President Obama authorised the use of United States air-power against Islamic State (IS) forces on 7 August 2014, there were just two stated purposes: to protect refugees, especially the Yazidi, and to counter any IS move towards the Kurdish regional capital of Irbil, the argument being that it was necessary to protect US personnel based in that city.
By that time there were reported to be around 1,000 US military deployed to Iraq because of the crisis. They joined US citizens already in the country employed in diplomatic, military-training or private-security roles, though it is hard to estimate the exact number (see "Islamic State, Iraq, America: a new front", 14 August 2014).
In the first few days of the air-strikes, few targets were hit, mainly IS artillery and logistics support that was considered too close to Irbil. There was some irony in this, since much of the IS equipment was American and had been seized by IS from Iraqi army bases in and around Mosul. It was, at least, good news for US defence companies, with their weapons being used by the US navy to destroy their weapons: a truly win-win situation, profit-wise.
Until mid-August, the US purpose seemed set. The function of the US forces would remain as originally stated, but it was expected that the operation would last many weeks (perhaps months). An important part of the plan was to allow Iraq's incoming prime minister Haider al-Abadi time to construct a more inclusive government and thereby undermine Sunni support for IS.
This all changed on 15-17 August as US forces substantially increased the tempo of their airstrikes, moving to aid Iraqi special forces and Kurdish troops to retake the Mosul dam, which IS had captured on 7 August. Over these three days, thirty-five out of thirty-eight airstrikes were intended to provide this support. US Central Command announced that the fifteen attacks by 18 August had “damaged or destroyed nine ISIL fighting positions; an ISIL checkpoint; six ISIL armed vehicles; an ISIL light armored vehicle; an ISIL vehicle-mounted anti-aircraft artillery gun, and an IED emplacement belt”.
Furthermore, US air-attacks are no longer provided by navy F/A-18s flying off the aircraft carrier USS George H W Bush in the Persian Gulf. They also utilise F-15E and F-16 strike-aircraft of the US airforce (USAF) operating from land bases in the region (probably in Qatar, such as the al-Udeid air-base) as well as from Predator armed-drones. The details are sparse, not least because countries in the region do not want IS to know that they permit bases on their soil to be used for US attacks against it.
Whether or not this can be described as “mission creep”, it is certainly the case that US military action has expanded considerably in the past two weeks, especially in the past five days. There are also indications of a further planned expansion, at least from the perspective of the Pentagon—if not the White House.
The IS calculation
Into this state of flux has now been inserted another factor, the brutal killing of the US photojournalist James Foley.
From the perspective of the Islamic State leadership, the murder serves four functions. The first is to demonstrate to its own paramilitaries that it can retaliate for the many of its own men undoubtedly killed in the US airstrikes, especially those around the Mosul dam.
The second is that the choice of a killer with an English accent will focus European and especially UK attention on what is happening—witness prime minister David Cameron’s rapid return from holiday.
The third is that it will send a signal to the American public that it has supporters who come from a closely allied state, an uncomfortable element given the refusal of the UK parliament to endorse military action on Syria in August 2013. Just how reliable is Britain?
The fourth and most important is a more subtle and potentially escalatory element, again no doubt deliberate. This is that the killing of James Foley sends a clear message of the fate any members of the US military captured by IS paramilitaries are likely to receive.
Even without this danger, US air operations in contested environments typically include a substantial "extraction back-up". Thus, if airstrikes are being conducted, standard operating procedure will be to have helicopter back-up available for retrieving downed aircrew. With this particular threat from the Islamic State, it is certain that any such operation will have major support: helicopters, airborne and within range at all times, with special forces and casevac personnel onboard, and with the helicopters themselves protected by helicopter-gunships and ground-attack aircraft.
All this takes serious resources. It should therefore be assumed US forces in Iraq are being (very quietly) expanded, principally at the base at Baghdad international airport but most probably in the Kurdish region as well.
Indirectly, therefore, the appalling murder of James Foley will ensure mission creep. And this is exactly what the Islamic State wants, for nothing would suit it more than for the US involvement in Iraq to expand rapidly. This may seem strange, given that US forces have successfully enabled Iraqi and Kurdish troops to retake the Mosul dam. But the Islamic State is not interested in the short term, and is willing to take casualties if these enable it to develop the narrative of the “far enemy” back in the Islamic world and doing its worst (see "ISIL, Iraq, and intervention", 16 June 2014).
Western analysts may see current developments as a path to subduing IS and creating space for an incoming government in Baghdad to develop more inclusive governance. IS, though, is in this for the long term. Just as the murder of James Foley has been a great shock, so IS may seek to arrange attacks in countries supporting US military action. These would most likely include Qatar and Bahrain (which houses the base of the US navy’s fifth fleet), and might also involve attacks in Baghdad.
From the perspective of Washington, the situation may be still be under control, with everything going more or less according to plan. A relevant question, however, is: whose plan?