Some time this week the Government is expected to invite MPs to vote on whether to extend the restricted scope of Britain's aerial bombing sorties against one of the cruellest terrorist organisations that humanity has ever seen. I hope very much that the vote takes place and the motion is carried.
This is not a knee-jerk response to the Paris bombings. The proposal is not offered in a spirit of vindictiveness, or neo-con ideology. This motion represents the sober judgment of the Prime Minister about how to make this country safer - in the short and long term - from a movement that poses a growing threat to our way of life. The rhythm of horror has been quickening: the killing of 30 British tourists on a beach in Tunisia in June, the Russian jet blown from the sky earlier this month, the Paris massacre two weeks ago - all of them claimed directly by Syria-based Daesh/Isil - to say nothing of many other grisly bombings and shootings around the world.
At home, British security services and counter-terrorism police are now obliged to monitor thousands of people who could intend harm to this country. The pace of activity has accelerated to the point where they are now making almost one arrest every day. A 15-year-old British boy was recently sentenced to life imprisonment - yes, life - for his role in a terrorist plot. He was radicalised over the internet. The men who corrupted him were based in the so-called Islamic State in Syria.
In June, a 17-year-old from Dewsbury became this country's youngest suicide bomber - again, after he travelled to Daesh-held territory in Syria. You only had to listen to the appalling delusions of the four women filmed in east London by Channel Four for the documentary ISIS: The British Women Supporters Unveiled, to see the effect of what is happening in Syria on the minds of impressionable and alienated young people. These women spoke of filthy Jews; they scorned democracy as being un-Islamic; and, above all, they looked with fascination and approval at the supposedly new holy kingdom that has been carved by violence from Syria and Iraq. "Nobody would have thought in our lifetime we would see the establishment of the Khilafah," said one.
This so-called Caliphate is not only the origin of an increasing number of plots against this and other countries - two of the Paris bombers, at least, were jihadis returning from Syria. It is a landscape of the imagination for the western would-be jihadis and those at risk of radicalisation. We rational people can see it for what it really is: a kind of Mordor, or the brutalised realm of Colonel Kurtz - where children play with decapitated heads, where prisoners are burned alive in cages, where gay people are thrown out of windows and where elderly women are shot and put in mass graves because they are deemed to have no use as sex-slaves. We see it as the home of an evil death cult. But in the minds of these potential recruits it has a dark charisma; a place whose very racism and viciousness somehow indicate a fascist purity.
As long as it exists, the so-called Islamic Caliphate will exercise a death-star tractor-beam pull on the mind of those who are willing to be deluded. The longer we tolerate the existence of this vast feculent breeding ground of hate - with a captive population of 10 million - the worse it will be for the world; and the more spores of terror will waft over the web and lodge in the minds of young people in European cities.
That is why this vote is not like the 2003 debate on the Iraq war, and those evanescent weapons of mass destruction. This time no one seriously doubts the threat. In the last few days, the UN Security Council has voted unanimously that "all necessary means" should be used to remove this haven for terror; and that is because every member of the security council - indeed every member of the UN - shares David Cameron's reasonable ambition: to degrade and ultimately to destroy this gangster statelet.
If you ask, very sensibly, how exactly we are going to achieve that objective by bombing from the air, then the answer pretty obviously is that we can't, or certainly not immediately. But that does not mean that aerial bombardment is pointless: it has helped to drive Daesh back in Iraq; and it will enable us to be of more use to those terrestrial forces willing and able to take them on in Syria.
Who are they? Whose boots will be on the ground? The only way to work that one out is to build international consensus, to create a coalition in which everybody - Vladimir Putin included - lives up to their rhetoric and turns their fire unequivocally on Daesh. That means more than just the 70,000 non-Daesh rebels, including the Free Syrian Army and others. It probably means brokering a ceasefire between Bashar al-Assad and the non-Daesh rebels, as well as agreeing a timetable for the eventual removal of Mr Assad, and gradually ensuring that all are focused on the common foe.
Of course it will not be easy; not when Mr Putin was yesterday bombing some of the anti-Daesh, anti-Assad rebels, and not when Mr Assad is actually buying oil from Daesh. The place is a writhing bag of snakes. But just as no British military action can be a substitute for a political deal, so no British diplomacy can be effective if we are only half engaged. How can we be taken seriously, if we fail to join a coalition of some of our closest allies?
To those who say we risk blowback, I say we already face a systematic terrorist threat; and it is wrong to contract out the fight. You cannot say the do-nothing option has worked: we have seen 240,000 people killed in Syria; we have seen millions displaced; the biggest refugee crisis in our lifetimes and terrorist plots emanating from the ideological cesspit of the so-called Islamic State. Of course bombing alone will not solve the problem; everyone can see that. But the military and political effort must go hand in hand, and Britain must be part of both. I hope Parliament votes resoundingly to join our allies in taking the fight to the enemy.