Within days even the debate’s high points were more visibly low points. The most impassioned and impressive speech of the day was given by Hilary Benn, the Shadow Foreign Secretary, speaking and voting against his party leader in voting for air strikes against IS in Syria. During his speech Benn appealed not only to the internationalist tradition of the Labour party but also to its anti-fascist tradition: IS were fascists, he said, therefore Labour should vote to bomb IS. Across the political spectrum the following day’s papers praised this speech as demonstrating not simply the qualities needed to lead a political party but the qualities of a potential prime minister. Few wondered why the rhetorical guns of Hitler and Franco — the heaviest weaponry in the arsenal of the British Left — had been deployed to argue for a handful of planes to join a single-digit percentile of missions across a border that no longer exists. Why the grandiosity? Why the sense of make-or-break over something so comparatively straightforward? As so often, it was the language that gave it away, and the fearfulness with which MPs used their words which showed what lay beneath.

Almost a decade ago Martin Amis asked the then Prime Minister, Tony Blair, whether he and other European leaders ever discussed the issue of growing Muslim demographics in Europe. “It’s a subterranean conversation,” was Blair’s response. But even subterranean conversations have a habit of occasionally breaking above the surface. Two years ago, in the pages of the Guardian, some of those fears made a rare such break. The private views of a number of senior figures at the Ministry of Defence were leaked to the left-wing paper. These expressed serious concern that “in an increasingly multicultural Britain” and “an increasingly diverse nation” there was a growing “resistance” to seeing British troops deployed, particularly in countries “from which UK citizens, or their families, once came”. British involvement in the Middle East and elsewhere was, in other words, becoming impossible because of what was happening demographically at home in the UK.

It is especially worth keeping this in mind today because of the phrase François Hollande used after the attacks in Paris. The President of the Republic declared France to be at war “both at home and abroad”. And so she is, and so we may well all be. But in 21st-century Europe, home and abroad are not such different things as they once were, and fighting a war in the skies above abroad is the easy part. Fighting the war at home is the difficult part. Because what do you do when the fastest-growing population in your country is a population which produces even a small percentage of a problem — a problem which whether we like the fact or not must obviously get numerically larger the larger that population grows?

One can of course try to tiptoe around this, and in Britain’s great parliamentary debate even the smarter and more experienced MPs did so. The former Defence Secretary Liam Fox may have a reputation as a rare hawk in British politics, but in an unpersuasive and almost apologetic speech even he spent his time making sure to stress, for instance, that the first and largest number of IS’s victims are Muslims (a point made, as it always is, as though it were the first time it had been made). This is true of course, but in the wake of the attacks in Paris and Tunisia it is also a deeply beseeching point to make.Perhaps this is now the only acceptable way to justify an attack on a group such as IS. Nobody seemed as keen to stress that the first victims of IS in Paris had simply been of any creed or none enjoying a night out at a restaurant, the football or a concert. Nobody made a priority of preventing IS’s ethnic cleansing of Christians. True, while rallying the Labour benches Hilary Benn was concerned to stress the group’s persecution of gays and older Yazidi women. But to single out these atrocities amid the vast panoply of IS barbarism says too much about our own priorities and too little about IS barbarism.