Patrick Cockburn

It was difficult at times to recall that the military intervention in Iraq being debated in the House of Commons involves sending six Tornadoes to bomb suspected Isis positions. It is very much a symbolic action from the British point of view. MPs seemed to be trying to grapple with the complexity of what is happening but not quite succeeding. Cameron and others made great play with the idea that military action is in support of a new, inclusive Iraqi government, when in fact it is as Shia-dominated as the old. Its most effective military strike force are Iranian-managed Shia militias but they, along with the Iraqi army, terrify the Sunni.

The killing of James Foley by Isis caused an upsurge of international revulsion and condemnation with harsh words from the US defence secretary and others. But the Obama administration is trying hard not to be sucked into a war that could be more serious than the US invasion and occupation of Iraq between 2003 and 2011. What Isis showed by Foley's very public murder is that it will always raise the stakes in any confrontation with the US and anybody else. It trumped America's reassuring portrayal of the recapture of Mosul Dam by the Kurds aided by US air strikes as a sign that Isis could be defeated.