When the 1998 Good Friday Agreement included a clause on the circumstances which would justify a vote on Irish unity, many commentators suggested that on the basis of the available evidence it was unlikely to become a reality.
Positions have changed decisively since then, and the comprehensive opinion poll in yesterday's Sunday Times which produced a range of significant findings on related issues should not have come as a surprise.
According to the survey, 51 pc of Northern Ireland voters want to see a referendum agreed by a secretary of state within five years, with 44 pc opposing the proposal and five per cent undecided.
It suggested a narrow majority, 47 pc to 42 pc, in favour of retaining the union, but when the question was put in another way, and asked about attitudes towards Irish unity, the outcome was a tie, with the respective totals for those who were pleased or upset by the prospect both sitting on 47 pc
Only 31 pc of English voters, and just 21 pc of Scots, were concerned about the arrival of a united Ireland, and the poll again confirmed a strong momentum towards Scottish independence, with 49 pc in favour and 45 pc against.
The overwhelming message which emerged was that Brexit had created an environment in which the democratic process is taking us firmly towards the final break-up of the UK.
As has been previously pointed out by this newspaper, the DUP's decision to campaign actively for EU withdrawal will probably go down as the greatest strategic mistake by a unionist party over the last 100 years.
Most rational voices warned the DUP against putting its faith in Boris Johnson, and the calculated way in which he eventually ditched his former allies was as brutal as it was predictable.
The dismissive comments on unionism expressed last week by George Osborne, who is editor in chief of the Evening Standard and was chancellor of the exchequer less than five years ago, probably represented a reasonable summary of wider Conservative attitudes.
Some senior DUP figures, as we have been reporting over the last week, are finally coming to terms with the need to prepare for a border referendum. They may yet come to regret that they did not reach this conclusion at a much earlier stage.
