We do not know yet if the final shape of Brexit is becoming clear, or if there will be no deal, or even if the UK will stay in, or return to, the European Union.
But I suspect that historians who will one day pore over the whole Brexit saga will see this week as a key turning point, that among other things, altered Northern Ireland’s constitutional position with the rest of the United Kingdom.
How did we get here? How did an internal UK border in the Irish Sea arise?
There will be many things to assess, first of all the national and international triggers.
Brexiteers such as the Tory MEP Dan Hannan, trace it back to 1992, when the EEC became a more expansive European Union.
Later there were the other signs of EU ambition such as the euro single currency.
In 2013, David Cameron committed to holding an In-Out referendum on Britain’s membership of the EU in a bid to placate Tory eurosceptics and stem the rise of Ukip.
He never thought he would be in a position to implement it because he never thought he would win an overall majority, but he unexpectedly did just that in 2015.
Then Mr Cameron judged it best to hold a quick vote in expectation of an early win before the notion of independence gained traction.
The EU, in the meantime, gave him next to nothing in the UK renegotiation to win better terms, and Mr Cameron returned claiming victory (and so disproved his comment that he would have been prepared to advocated Leave if he got nothing from Europe).
He then had the bad luck of the migrant crisis in late 2015 heightening concerns about immigration.
Famously, in June 2016 Mr Cameron lost the referendum.
Meanwhile, something dramatic had happened that led to the next trigger. Jeremy Corbyn was elected Labour leader in 2015, and was so radical that he was treated with contempt by his own MPs, who even isolated him in the chamber.
In 2016, he faced a leadership challenge, a mere 12 months into the post. Everyone said he would never win a general election.
To the Tories’ delight, he saw off that challenge.
By early 2016, Labour ratings were lower than they had been since the Second World War. A Corbyn premiership was seen as almost impossible.
Quite understandably, Theresa May thought she not only could win a snap general election, but was in a better position to do so than almost any incumbent prime minister. This would strengthen her Brexit negotiating hand.
When the exit poll came through on June 8 at 10pm, my two simultaneous thoughts were: that the conventional wisdom on Jeremy Corbyn had been shown to be rubbish and he might well one day be PM, and that Mrs May would struggle to get Brexit through. So it has proved.
While the story in London is mainly one of miscalculation, the story in Northern Ireland is partly one of miscalculation but mainly one of indifference.
In July 2014, I wrote an article about the possibility of Scotland voting to leave the UK, and the UK quitting EU – a scenario that would “rock Northern Ireland to the core”.
Yet there was almost no interest here in that Scottish independence referendum, not until the last fortnight in September when polls suddenly found that the race was tight.
Unionists seemed unaware of the huge risks to us in NI of a Scottish departure.
Two years later, in 2016, there was a similarly low level of interest in the Brexit campaign, until the final weeks. And even in those final weeks, the debate here focused more on the national question, than the local implications (even though grandees such as Tony Blair and John Major warned about them).
It is wrong though to say, as some people now do, that the DUP or unionists campaigned strongly for Leave. A number of unionist politicians did so, and they were more visible than unionist supporters of Remain. But most unionist politicians were muted in the campaign.
There was certainly no significant sense of any threat to the Union, unlike in Gibraltar, where concern at how Brexit might impact its status as British led to a 96% vote against quitting the EU.
It is often said that some key unionists were relaxed about Brexit because they thought it would not happen, but that cannot explain the lack of any sense of danger in the two-and-a-half years that have elapsed since the referendum and the casual, repeated calls for NI to leave both customs union and single market, like rest of UK.
Why is this? An obvious reason is the Tory-DUP deal, which made it harder to envisage Theresa May doing anything that might cause her government to collapse.
But then there were was the disastrous backstop of December 2017, which showed the government was more concerned about meeting the concerns of another jurisdiction, the Irish Republic, than of its own territory, Northern Ireland, despite being propped up by NI MPs.
Unionism has been in denial since December, partly because the DUP secured paragraph 50 to the backstop, which seemed to rule out an Irish Sea border. And so a sense of calm continued to prevail.
The Ulster Unionist Party points out that it opposed the backstop, as it did, and as did I and most unionists. The DUP had to put a brave face on it, given their position.
Despite all this, there has been no sense of danger until now.
The backstop meant that NI will never be able to leave the EU customs and regulatory space. It means a permanent Irish Sea border, and a major one if the UK in future leaves the customs union as well as the single market, while we are forced to stay in both.
The complexity of Brexit and all its elements is a major reason that there has been no sense of danger.
But another reason is that many soft unionists seem not to care about constitutional damage. They are apathetic, happy with an invisible border in the Irish Sea that gives us access to EU markets.
I am not aware of any significant opposition in the Alliance Party, which was once solidly pro Union, to its stance, which accepts a border in the Irish Sea but not at land.
I might be attracted to the so-called ‘best of both worlds’ myself if I was not deeply worried about the long-term implications with regard to our unfettered access to the United Kingdom market.
Now, in a fresh difficulty for unionist politicians, business leaders are coming out in force in defence of Theresa May’s Brexit deal.
This is a huge problem for unionists. Some might hope for no deal, but it is clear the Tories and Labour will do almost anything to avoid that outcome, including, as we have seen, accepting the Irish Sea border they all said they opposed.
• Ben Lowry (@BenLowry2) is News Letter deputy editor