If Islamic State is to be defeated, it must be attacked in both Syria and Iraq

Parliament will today vote for the motion authorising air strikes by the RAF against Islamic State in Iraq. The motion with its promise of a further vote before any action is taken in Syria and a commitment not to put troops on the ground has been designed to pass as easily as possible. Understandably, no one in Downing Street wants to risk a repeat of last year’s Syria vote.

But the reasons why the motion will pass are also the reason why it is not fit for purpose. Islamic State has succeeded in rendering the border between Syria and Iraq meaningless, it operates on both sides of it. But British planes will only hit Islamic State on one side of this line.

There are many arguments for striking Islamic State in Syria too.