"The evidence is there for all to see what happens in the absence of cooperation. It leaves a political and military opening for extremists."- William HagueWith Washington said to be ready to intervene militarily along with Iran to roll back the threat posed to Bagdhad by the ISIS, it is vital to remember that the Obama administration has claimed it is prepared to use air strikes against it both in Syria and Iraq.
As ISIS has its main base in Raqqah, it owes its surge deep into Iraq through Mosul and Tikrit not merely to the continued chaos that has not gone away aftermath of the Iraq War but also due to the fact that the US and Britain have been tacitly backing fanatical Sunni jihadists in Syria.
That is why Obama and Hague focused solely on the failings of the Shi'ite government of al Maliki in Baghdad as a way of diverting attention away from the fact that ISIS were fighting with the Free Syria Army as recently as 2013, a force backed by Britain and the US as a means to overthrow President Assad.
ISIS was not only able to develop due to the way Sunni jihadists groups have become progressively more brutal in northern Syria. The group owed the bulk of its past funding to donors in Saudi Arabia, Qatar and Kuwait where it was regarded in Iraq as a means to combat Shi'ite militias and Iran's influence.
Hagues' propaganda use of the flexible cant word 'extremist' means 'jihadists not under our control' or else not objectively on the side of Britain's Gulf allies in Saudi Arabia and Qatar, both of which have been vying for influence in any post-Assad Syria by promoting the most effective .i.e. ruthless jihadists.
The absurdity of the geopolitical situation in Syria and Iraq is such that Britain and the US are effectively backing Al Qaida affiliated groups such as Jabhat al-Nusra by funnelling weapons to the FSA which only in the course of 2014 has been fighting against ISIS.
One reason is that whereas the FSA and ISIS had a common interest in fighting Kurdish separatists, ISIS wanted to surge into Iraq and the Kurdish separatists were prepared to do a deal with ISIS to allow them to march southwards and link up with Baathists opposed to the Shi'ites in Baghdad.
The reason is that Kurdish separatists in Syria and the autonomous region of Iraq wanted to seize Kirkuk which they consider the ancient ( and oil rich ) capital city of Kurdistan. By having ISIS put pressure on Baghdad and fight against the FSA they could increase their reach and power over their territory and oil
The US and Britain would be prepared to shore up al Maliki's Shi'ite government only upon certain conditions so it can continue to exert influence in Baghdad and to prevent Iran from increasing its role in Iraq through sending troops , signing lucrative arms deals and shipping weapons to Assad.
Hence the other reason-apart from the potential threat to the oil producing regions south of Baghdad- for military intervention by the US, with British intelligence assistance, is to reduce ISIS so as to effectively back up the FSA's struggle and ensure the goal of 'regime change' in Damascus is furthered.
Generally, ISIS is an offshoot and product of the increased radicalisation and competition for control amongst Sunni jihadists and, as such, a product of Saudi and Qatari foreign policy backed by Britain and the US. But it is seen as a threat because it has allowed Assad to regain the military initiative.
Throughout 2014 Assad has been rolling back the FSA from positions around Damascus and the strategically vital land between the Syrian capital to the Mediterranean coast, the route through which arms are supplied to the government and that connects to Hizbollah's base in Lebanon.
ISIS poses a threat because it has divided the Sunni jihadists in Syria and allowed Assad and hence Russia-which backs Assad and has an interest in blocking Qatar's and Turkey's plan for a gas pipeline that would rival its supply to Europe-to gain the upper hand in the Middle East.
On the other hand, the fact that ISIS has been able to collude with the Kurdish militias to threaten the Iraqi capital provides an opportunity for Washington and London to make any military assistance conditional on moving away from Tehran ( that's what Hague really means by the 'need for cooperation' in Iraq ).
Ultimately, US and British foreign policy is about energy geopolitics and siding with key regional allies which provide them with oil ( as Saudi Arabia does to the US ) and with the large and increasing quantities gas which Qatar provides to Britain and France, thus allowing it to diversify supply away from Russia.