In 1918 the United Kingdom as it had existed was blown apart by a trifecta of landslides; a Tory landslide in Great Britain driven by a three-way split in the centre-left vote; a Sinn Féin landslide in most of Ireland; and an Ulster Unionist landslide in what would soon become Northern Ireland.

This election is more most consequential than any in the 101 years since, and it too has been marked by competing landslides: a Tory landslide in England and Wales such as has not been seen since the days of Margaret Thatcher, and in which Boris, unlike Bonar Law, has not needed to depend on a badly split opposition; and an SNP landslide in Scotland that matches that of 2015. Brexit will happen by the end of January; the internal debate within the SNP will have been settled entirely by this result and we can expect a second independence referendum relatively soon after the next Scottish Parliament elections in 2021. This will occur with or without the agreement of the UK government, with the prospect of a Catalonia-style situation heaving to with frightening speed.

Corbynism is definitively over, but so what? The phenomenon will soon become as interesting as Michael Foot’s tenure as Labour leader, except there is no way with any credibility of blaming its failure on centrist splitters. Labour squeezed the LibDems into oblivion during this campaign.

As for Northern Ireland, who knows? I write all this without knowing anything about votes cast in NI constituencies, but I doubt that matters much. We are now at the mercy of external forces well beyond anyone in the region’s capacity to control. What will emerge is, however, unlikely to be a pretty picture. The Johnson deal will be implemented as planned, and in less than two months. The moment for gloating at the DUP’s discomfiture at their brutal treatment by Boris has passed. Yes, they were arrogant and complacent; yes everyone else could see what was coming even if they didn’t. One could argue they deserved it. Yet one must remember that as they have been viciously treated, all of us can be viciously treated by a man who asked, “Aren’t they all called Murphy?”

There is no credible means for Unionists to oppose Johnson’s deal when he is set to hold such a commanding majority in Parliament; it is difficult to see how the anger in the Betrayal Act meetings can be directed into any meaningful attempt to secure change. Johnson simply does not care. Unionism will be left with a series of passionate and perhaps even occasionally brilliant speeches in the House of Commons as the Conservative machine steamrollers over it, just as was the case in 1986. But who beyond the historical anorak now remembers the spellbinding speech of a cancer-ravaged Harold McCusker that brought the Commons to silence?

I realised the depth of the Unionist predicament when even Adrian Hilton, the trenchantly Conservative and Protestant blogger once sacked as a Tory parliamentary candidate for his stringent anti-Catholic views, called on the DUP to support Johnson’s Brexit deal. Even the few Englishmen who have professed to truly love Unionist Ulster for what it is regard betraying it as an acceptable price to pay for their own ‘independence’. If it’s a choice between Brexit and Ulster, then Ulster will have to put up with whatever is imposed on it. After all, the loss of the much more valuable real estate immediately across the North Channel is also considered an acceptable cost. The fertile brains of Dundela Avenue will ask themselves were they really wise to go all in on the Brexit project in 2016 when the risks to the Union were so great, but that is now spilt milk under the bridge.

Nobody in Northern Ireland seems yet to have grasped that, for the first time since the wars of the Reformation, our conflict is destined to sit astride a geopolitical faultline. As yet another NATO summit has yet again shown, Europe and the United States are further apart than for generations and the direction of travel is negative. How will our various factions manipulate and be manipulated by the tensions between a loyally pro-EU government in Brussels and a Westminster government which is going to be committed to a Trumpean vision of a new global order? The 17th Century, you’ll doubtless remember from your schooldays, wasn’t a whole lot of fun in Ulster.

Sinn Féiners see the headline figures in polling on the border and can scarcely contain their excitement. They must ask themselves if they are the best people to lead Northern Nationalism during a possible border poll campaign, and still more ask themselves if they are the best people to reassure angry and frightened Unionists the day after a narrow vote for reunification. Many who, frankly, despise Nigel Dodds will have felt a cold shiver at John Finucane’s refusal to condemn his attempted murder in a hospital as he visited his sick child. If defending the Troubles-era record of the IRA costs the chance for a United Ireland, Sinn Féin seems, bizarrely, to see that as an acceptable price to pay.

Yugoslavia descended from enlightened co-existence to savagery in a few short years. We must not delude ourselves that we are not capable of such bestial rage; we have long matched the horrors of Bosnia in brief encounters if never in sustained fury.

This is the beginning of the end of the United Kingdom, and I have no vision of what the future might look like beyond a terrible sense of foreboding.