Al-Qaeda’s followers seem acutely vulnerable to the sin of hubris. It was only natural for the Islamic State of Iraq and al-Sham (ISIS) to take advantage of Syria’s civil war to carve out a new domain inside that country. It was perfectly logical for them to turn this area into a launch pad for a grand offensive back into their old heartland in Iraq. But was it really necessary for them to move so far and so fast?

In particular, the rationale behind capturing Mosul, a city of 1.8 million people, and then advancing another few hundred miles to threaten Baghdad itself is highly questionable. With only a few thousand fighters, how can ISIS hold all of this territory? True enough, the Iraqi army simply collapsed before their eyes, so it must have been hugely tempting to press on and on. But the chances are that ISIS have now over-reached and made their own defeat a compelling necessity for a remarkable coalition of enemies. When you manage to unite Iran and America against you, then you know you really have gone too far.

The chances are that the ISIS surge has now reached its peak and a fightback will begin. It really is a remarkable moment when America, Iran, Bashar al-Assad and the Sunni kingdoms of the Gulf all find themselves on the same side. Can there ever have been a more unlikely coalition, or more compelling evidence for the truth of the old dictum that "my enemy's enemy is my friend"?

David Fuller's view

There is a long history of invading armies advancing too quickly and leaving themselves vulnerable to shortages of supplies.  Stories of ISIS’ gratuitous violence against Iraq’s army and also civilians will have made few friends on route.  However, ISIS has actually strengthened its supplies by picking up weapons quickly discarded by the demoralised opposition - from rifles to rocket launchers, artillery and tanks – provided by the USA when President Obama pulled US forces from the region. 

Despite these gains, ISIS has a small number of troops and would certainly be vulnerable on the move from attacks by drones and air force raids, if the USA participated along with other forces.  Needless to say, this is the last thing that President Obama or any other Western leader wants to do but it might be cheaper in the long run if it kept the region’s oil flowing. 

Alternatively, Obama could decide to block any further US military involvement in the Middle East, knowing that it would be unpopular at home, not least as America is now all but energy independent for decades to come.  However, it the M/E slides into additional turmoil which further reduces the region’s oil production, causing crude prices to spike higher, global GDP growth could experience another downturn. 

You may also be interested in this Bloomberg article: Jihadi Recruitment in Riyadh Revives Saudi Arabia’s Greatest Fear.