Dr Julian Lewis:  It is always a pleasure to hear my right hon. Friend talking about this subject; although it is a grim subject, the depth of his knowledge is always enlightening, and I would hope that at some stage we might have a debate rather than just an update statement so that we can engage with him more fully. May I therefore raise a couple of points?

First, does my right hon. Friend accept that ultimately the reason Daesh was defeated was that, by seizing and holding territory, it gave up the terrorists’ best weapon: the cloak of invisibility? Secondly, the only thing I found missing from his statement was any reference to that part of Syria that was not fought upon and occupied by the Kurdish-led Syrian Democratic Forces. Can he explain what percentage of the country is occupied by forces other than the Kurdish-led forces? Is not a large percentage of the country occupied by the forces of Assad? Does he now accept what the Government have denied all along: that if we wanted the insurgency in Syria to be defeated, the logical consequence – unacceptable though it seems – was going to be that Assad was at least in part going to win, given the support of his Russian backers?

[The Secretary of State for International Development (Rory Stewart): These are two important challenges from the distinguished Chairman of the Defence Committee. I shall take the second one, then move on to ​the first. It is of course true that the vast majority of Syria is now in the hands of Bashar al-Assad’s regime. Looking back in time, we can see that the optimism of the United States and the United Kingdom that Bashar al-Assad would inevitably be defeated, and the red lines that were created by President Obama and others, have not been vindicated in any way at all. In fact, with Russian backing, the Syrian regime has not only retaken the land right the way up to the Euphrates – the edge of the area we are talking about with the SDF – but has pushed south to the Jordanian border and is now pushing up to Idlib, having taken Aleppo and the rural areas around Damascus. The Chairman of the Defence Committee is absolutely correct in his assessment of that. That does not answer the bigger question, which is what Governments such as those of the United Kingdom or the United States will choose to do with the Syrian regime in the future. This returns us to the kinds of challenges that we faced in dealing with, for example, the Shi’a community in southern Iraq under the brutality of Saddam Hussein. How on earth do we balance our humanitarian obligations towards people in horrifying conditions with our sense that we do not wish to operate in the territory of a man who, whatever the sequence of his military successes, remains an unbelievably brutal murderer who is clearly associated with the execution of unarmed prisoners and countless persons through the deployment of chemical weapons. That will remain the key issue for the House to consider over the next months and, indeed, years.

On the first issue, the Chairman of the Defence Committee is also absolutely right. One of the most bizarre, peculiar and ultimately self-defeating parts of Daesh’s campaign was its decision to try to hold territory and, in particular, to try to take on conventional forces. The entire idea of an insurgency or a terrorist organisation is supposed to be that it should drift around like mist or, to take Chairman Mao’s analogy, that it should work and feed off the consent of the local population. Daesh did neither of those things. It attempted to hold territory and, in Kobane, to take on 600 US airstrikes. It attempted to alienate the entire population that it was trying to depend on, through its brutal videos and its incredibly horrifying Islamic social codes. What is extraordinary is not that Daesh was ultimately defeated but that it remained so successful for so long and was able to hold this territory for such an extended period of time.]