If a new Brexit deal is agreed between the UK and the EU – which is still very far from certain – the main reason will be that Leo Varadkar and the Irish Government are pushing for one.  Early last week, the chances of an agreement seemed to be weakening: Downing Street briefed an account of a phone row between Boris Johnson and Angela Merkel; Dominic Cummings gave a ferocious No Deal briefing to the Spectator.  But by the weekend, the prospect of a deal was strengthening: the Prime Minister and the Taoiseach had met in the Wirral, and agreed that there was “a pathway to a possible deal”.  What had happened?

The answer is that we won’t know until the history books are written.  Perhaps we were all being played, and a deal was always likely.  Nor can any of us see more than the haziest outline of what an agreement might look like – if, as we say, one in reached at all.

Nonetheless, it is possible to glimpse some certainties through the mist.  To date, Ireland has insisted on maintaining the backstop – or to be more accurate, the Northern Ireland and Ireland Protocol, which is part of the Withdrawal Agreement.  Why has Varadkar changed his approach?

We suspect that there are two main reasons.

First, the Taoiseach seems to date to have taken what this site has called a rational gamble (a form of words echoed last week in the Cummings briefing).  This seems to have been that there would be a further extension rather than No Deal; and that this would sooner or later be followed by Britain revoking Brexit, perhaps after a second referendum, itself brought into being by a Labour or “national unity” (i.e: Remain) government.

All that may still happen – especially the extension.  But Boris Johnson’s ratings are holding up surprisingly well, given his reverses in the courts and the Commons.  There appears to be no consensus for replacing him either with Jeremy Corbyn, or with a Ken Clarke-type Remain government Prime Minister.  Next Saturday, there is likely to be a push for second referendum in the Chamber.  But over at the UK in a Changing Europe, Alan Wager writes that “unless the Tory Party splits again, the numbers are difficult to envisage”.

Which would open the door to a general election sooner rather than later; a possible Conservative majority, and a consequent No Deal Brexit – or else a new negotiating offer from Johnson distinctly tougher than his previous one.  Ireland’s Government follows British politics closely and its Embassy is never less than well-informed.  We suspect that it has picked up the change in the weather.  The odds on that rational gamble have started to look a bit longer.

Second, Ireland doesn’t seem to lose anything of real value to it from what Johnson’s proposal is understood to be.  (Stephen Booth of Open Europe gives an account on this site today.)  You might argue that if Northern Ireland joins the rest of the UK outside the Customs Union, and is thus able to benefit from post-Brexit trade deals with third parties, that Irish produce may be undercut in our markets by cheaper goods: about two-fifths of Irish agri-food exports come into the UK.

But in our view protecting the interests of its farmers has not been Ireland’s main aim in the negotiation.  Were this so, the EU would not originally have proposed a backstop that left Great Britain outside the Customs Union.  Rather, Ireland’s principal objective has been to maintain its land border with the UK much as now, in line with its strategic aims and its reading of the Belfast Agreement.

Johnson’s proposal seems to concede this.  Under it terms, Northern Ireland will apparently stay in the Single Market and there will be no North-South customs border (nor a DUO veto).  The European Commission is worried about the leakage of goods from Great Britain into the Single Market.  But preventing one is not a priority for Dublin.  The Irish Government is primarily concerned with the politics and economics of the island of Ireland.

So where next?

For as long as Ireland insisted on preserving the backstop, other EU countries were unwilling to gainsay it.  There was some evidence of irritation with the country’s stance in Eastern Europe.  And the German Government seemed relatively inclined to cut Britain some slack.

But ultimately the EU was not going to rat on one of its own – at least in the Brexit negotiations – and its bigger states need to show that they are mindful of the interests of smaller ones.  However, Varadkar’s shift of view may have turned the EU’s position on its head.

For where before it had an interest in not engaging with the UK’s idea, it now has one for doing so: keeping Ireland happy.  Before Brexit, it and the UK were close allies within the EU.  Brexit has pushed the two countries apart – at loggerheads over a potential settlement.  Now they are once again working closely together, however briefly, to implement what seems to be a variant of the Ruperal Plan.  Anglo-Irish relations thus have the chance of a reset.  The Johnson Government must maximise the opportunity.  As ConservativeHome has said many times during the negotiation, the UK has paid a high price for underestimating and overlooking Ireland.