So, Theresa May does not want to take the risk that "moderate nationalists" in Northern Ireland will vote us out of the UK. Jacob Rees-Mogg has a different view. He thinks they are very unlikely to break the golden link of the Union and that Northern Ireland is as safely joined to the motherland as is Scotland.
That thought alone should unnerve our local unionists, who have long thought they were a lot safer even than that.
Declan Kearney, of Sinn Fein, responded excitably. The very fact that the Prime Minister thinks a referendum could deliver a united Ireland arguably obliges her to call one, according to the Good Friday Agreement. But, on reflection, he decided that it might be better to defer a referendum for up to seven years to give people time to get used to the idea. So, no change in Sinn Fein's position after all.
Theresa May's calculations are, perhaps, based on intelligence studies that disclose more than we know. Or it might be that she is unduly anxious.
That's what a lot of people think after reading in The Times that the Prime Minister doesn't want what is called "our wee country" to slip through her fingers. Breaking up one Union during her tenure in Downing Street is quite enough for the historical record without losing another, as well.
But she is right about one thing. The future of the Union between Northern Ireland and Great Britain, the integrity of the UK, is indeed in the hands of the people she calls "moderate nationalists".
We can safely say that the majority of unionists, drawn from the Protestant/British identifying section of the population - just under half of it and declining - will vote in a future border poll for staying in the UK. We can similarly assume that a large section of the Catholic/Irish identifying community will vote the other way, for a united Ireland.
And that leaves me and people like me who have never been much fussed about Irish unity, but do identify as Irish. This is a community of people who perhaps vote for the Alliance Party, or the SDLP, or no one. They work in the civil service, in education and the hospitals and in journalism and other professions, all walks of life really.
I think of a friend of mine, an old Catholic grammar school boy who has on his office wall a photograph of himself shaking hands with Prince Charles. I remember his response to the Drumcree stand-off: "They can walk through my bloody kitchen if they'll only knock the door first and ask permission."
The emergence of a "Catholic" majority in Northern Ireland may seem to Theresa May to augur a united Ireland, but actually it could work differently. Catholics will no longer be a minority that can be oppressed, or ignored; that's for sure. Northern Ireland is now as much theirs as anybody's. The concept of a "Protestant Ulster" is dead.
In those circumstances, more "Catholics" might, in fact, feel inclined to just leave things as they are. They will know that they can force unity later on, if they wish, so why not just bank that?
These are people whose parents helped run Northern Ireland when Catholics were spoken of in the political centre as if they did not really belong.
They made the full contribution of citizenship with one major reservation; most were disinclined to join the RUC. Why would they want to overthrow the state in times that were more comfortable for them?
Well, there is Brexit. There is a major political row around this, which dismisses the Irish Republic as a country with little right to place itself anywhere but in Britain's armpit to serve her bidding.
There is a widespread failure among unionists to comprehend the offence implied in their support for Brexit. Those "moderate nationalists" who served the state through the bad times might feel they deserved a little reciprocation, yet find unionists utterly blind to the significance of Europe.
And it is not just about whether there will be a few cameras at the border; it is about the historic tension between Britain and Ireland having been resolved in a European context.
If those two countries don't bristle at each other, it is better for relations inside Northern Ireland between people who identify as Irish and British. And this matters most to the "moderate nationalists", who were not asking for very much more than stability and respect.
Unionism seems to presume that identity concerns motivate them, but that the "moderate nationalists" will contentedly vote in their best material interest. Well, they might turn out to be as bloody-minded about their identity as the British in Ulster and the English nationalists, who would rather be poor than in the European Union. They might also find, after Brexit, that they would be better off back in the EU and they will have the border poll to arrange that.
What is unionism to do about this? Arlene Foster said, foolishly, that in the event of a united Ireland, she would leave. The danger is that, if others think the same way, they might see sense in leaving before the rush and accelerate the process.
One has to worry that unionists would see a border poll as a sword of Damocles hanging over them. In truth, that is what it will be unless they can make the cultural adaptations that accommodate "moderate nationalists".
What we are seeing is a unionism which has little sense of where its own interest lies. That is in assuaging a fear among the "moderate nationalists", who might preserve the Union, or crash it, that their contribution is acknowledged and valued.
What we have seen, instead, is a smug unionism, which gives itself all the credit for the Union and identifies that Union as Protestant and reverential of the Army and the imperial tradition.
Ironically, this is a conception of Britishness which makes unionists look like oddities in England. Northern Ireland, hampered by their social conservatism and evangelical religion, looks like a redneck backwater. The Irish Republic, by contrast, looks liberal and secular. Or, at least, is moving a lot faster in that direction.
Now, we can think of missed opportunities to respect the Irishness of the "moderate nationalists" the fact that there was no unionist representation, for instance, at Seamus Heaney's funeral.
At the start of the year, I was at the funeral of the former senior civil servant Maurice Hayes, a gael. And while there were Protestant clergy and some unionists there, there was no formal state gratitude for the work he did, on which the security of the Union depended.
It might be too late. Brexit combined with demographic shift might well finish off the Union in a decade.
But Theresa May has disclosed her ignorance about Northern Ireland already this month, so she may be wrong in her fears about Irish unity.
Then again, she has spent more time sitting down with the DUP than most of us and maybe it is sinking in with her that these people are appalling and don't even see where their own interest lies.