The charges against David Cameron over his Iraq policy are well founded. But there are extenuating circumstances.
One accusation is that it makes no sense for him to emphasise in such stark terms the danger presented by IS and then rule out so categorically the UK's taking part in any military action against the jihadists. Cameron's position lacks logic; but it's excusable. As others have pointed out, the humiliation of last year's vote when the Commons stopped Cameron intervening in Syria's civil war has left its mark. He dare not risk this happening again despite, so we are told, his personal belief that Britain should be taking military action with America against IS.
His position will hold for the moment. But what happens if the US and, say, France decide that a much greater military intervention alongside the Kurds and the new Iraqi government is necessary to defeat IS? Despite Obama's caution, this is possible. If so, it is surely unthinkable that Britain, with its responsibilities as a Permanent Member of the UN Security Security, could stand aside from military intervention. In which case, thanks to the blighted precedent set by Tony Blair in 2003, Cameron would have no choice but to return to the Commons for authorisation to go to war in Iraq - again.
Against this eventuality the National Security Council needs urgently to start preparing the arguments why, if it was wrong to go into Syria in 2013, it's right to go into Iraq in 2014. Fortunately the case is clear. The establishment of a violent, extremist and militarily proficient theocracy athwart Syria and Iraq could mark the beginning of the end of the frontiers put in place after the First World War and the dissolution of the Turkish Empire. The ambitions of IS are apparently boundless. Lebanon, Jordan and Saudi Arabia (a caliphate in all but name) will all be in its sights. Whatever the imperfections of frontier-drawing nearly a century ago, it is in absolutely no-one's interest that the sovereign states so created should be wiped from the map. The entire world order would be destabilised.
The case for intervening against IS is therefore compelling in a way that going into Syria in 2013 and Iraq in 2003 never was. In Syria it was always fanciful that a "boots-on-the-ground" intervention by the US/UK/France would have handed the rebellion against Assad to moderate forces, so pre-empting the creation of the then ISIS. A rule of war is that the advantage lies with the most violent and best organised. Western armies might well have found themselves fighting Assad simultaneously alongside and against Al-Qaeda/ISIS.
Which brings us to the second charge against Cameron: that there is no strategic coherence in the UK's approach to the Middle East. The charge is again well based. How do we find ourselves simultaneously working for the downfall of a Shia dictator in Syria, backed by Iran, while contemplating collaboration with Iran against Sunni jihadists in Iraq, who have been fighting Assad?
Again, this is not entirely Cameron's fault. It is more the result of a structural weakness, long present in British foreign policy. Pragmatically, we have always supported stability and those who preserve it - that has meant autocracies and dictators. Rhetorically, we have always supported the establishment of democracy. For decades we were able to get away with this contradiction in the Middle East. But the so-called Arab Spring blew it wide open. We rushed to support the photogenic protesters of Tahrir Square against President Mubarak of Egypt. Chaos ensued; the democratically elected Muslim Brotherood government of President Morsi was overthrown; and the military returned to power under General Al-Sisi. In the West there has been hardly a peep of protest as "stability" has returned to Egypt.
As for Syria, the uprising against President Assad in the name (for some) of democracy has led directly to the creation of IS. We are, like it or not, in de facto alliance with Assad against IS.
It is time for a root-and-branch review of the principles of British foreign policy, so that they reflect two essential things: the world as it is and not as we would wish it to be; and the British national interest. Or, to put it another way, don't do nation-building and don't intervene in other people's civil wars - we usually make things worse, as in Iraq, and the waste of blood and treasure is unforgivable.
If this means hobnobbing with dictators, so be it. Only genocide and threats to world order merit military intervention, as with IS. For the rest, nations must be allowed to find their own destinies. After all it took Britain 713 years after Magna Carta, undisturbed by foreign invasion, to give women the vote.