Let’s imagine for a moment that the EU now takes its lead from Donald Tusk, does what Parliament and not the Government wants, and decrees that it will give the UK a further extension of three months or more.

In this event, any impetus that Boris Johnson has gained by winning Second Reading for his Withdrawal Bill would be lost.  Instead, there would be a pause, which in turn could hollow out into a vacuum.  The Government would probably try to press on with the Bill – since it can’t seem to win the vote for a general election it needs under the terms of the Fixed Terms Parliament Act – but its opponents would push for a second referendum instead.

They might not get it but, amidst the stagnant waters of this lengthy extension, Johnson’s boat would float inertly.  Few would think that a long extension would be the last.  MPs would not believe that they were faced with a choice of the Prime Minister’s deal or No Deal.  The Commons would risk drifting back to where it has been until yesterday: unable to resolve itself in favour of anything.  The EU would have sunk its own deal.

Now suppose instead that it grants a very short extension – say a fortnight or so – along with a statement that is losing patience with Parliament.  The consequences would be very different.  The EU would be framing debate in the way that Johnson wants: his deal or No Deal.  That would give the 20 or so Labour MPs who voted with him yesterday, plus the likes of Philip Hammond, an incentive to stick with him in the lobbies.

Yes, he would miss his Brexit deadline of October 31.  He would neither have done nor died.  But as Lord Ashcroft’s research and the polls suggest, the Prime Minister is getting the benefit of the doubt from most voters.  They are sick of delay.  They want Brexit done – hence his use of the phrase..  Most would doubtless continue to blame other MPs, not Johnson himself, for missing that end of October deadline – if (and it is if) Brexit were then duly delivered.

Now suppose that it grants no extension at all.  This is best of all for the Prime Minister, because it potentially opens up a choice.

On the one hand, he could say to voters:  “Right, that’s it – we’re now out of the EU.  I propose a settlement with it based on my deal.  Give me a mandate.  Let’s have that general election now.”  This would be the big, bold, brave course to take – to hit Labour while its Brexit policy is still is disarray and Jeremy Corbyn is still in place.

On the other, he could simply try to ram the Bill through during the next few days, assuming that the EU acts quickly.  Based on yesterday’s vote, and with a No Deal cliff-edge facing MPs on October 31, we suspect he would succeed.  And he would have Brexit with a deal, rather than Brexit without.

There is a case for taking option one, but there’s a snag – namely that, as we have seen, the Prime Minister can’t force an election, because of the Fixed Terms Parliament Act.  He has already tried twice, and failed.

At any rate, no extension at all is clearly best for Johnson – which is why he made a monkey out of the Benn Act by sending a second letter to the EU contradicting the request for extension contained in the first.

However, the EU is unlikely to grant no extension, for a mix of reasons.  Some EU member states won’t want to rescue the Prime Minister.  Others won’t want to intervene, as they see it, to Britain’s internal affairs.  Others still will simply want to proceed at the pace of the slowest member.  Few institutions do stasis better than the EU, and it may pursue it in this case.

None the less, note what is going on.  It’s not so long since all Brexit choices looked bleak for the Government.  Under Theresa May, there was a sense that things could only get worse, as Brexit Day was repeatedly postponed and European elections enabled.

Now, the options for Johnson look much better.  Maybe Emmanuel Macron will get his way, and an extension will be vetoed after all.  Or perhaps the extension will be short, paving the way for Brexit by mid-November.

This is the real lesson of yesterday evening.  The progress of the Prime Minister is two steps forward, one step back.  He loses the programme motion.  But he gets Second Reading – a moment of immense symbolic importance. This was the first time since Brexit in which the Commons had actually voted for anything other than in the most indicative of votes.

As he inches forward, like a prop forward grinding through mud towards the line, options begin to open up; choices can be made; the clouds start to lift.  One wheel off May’s wagon, and she was in the ditch.  One wheel on Johnson’s, and he’s still rolling along: higgity, haggity, hoggety, high.

Over in EU Towers, Tusk wants a long extension, or says he does.  (Perhaps we’re being spun.)  Macron proclaims himself in favour of none at all (ditto).  But perhaps neither are the key player, and to find him we should look closer to home.

The main reason why May’s deal failed was the backstop – the UK-wide version which emerged from the Northern Ireland-only original.  And the reason why Johnson’s original gambit didn’t succeed was ultimately the same.  Ireland wouldn’t accept alternative arrangements instead, at least not immediately after Brexit.  And both the Commission and other member states made a song and dance about standing with Ireland.  The bigger counties, like France and Germany, didn’t want to be seen dumping on smaller ones.

If this deal is the EU’s as well as Johnson’s, it is so because of Leo Varadkar.  It was their summit in the Wirral that kick-started the Brexit talks back into life, after the Prime Minister’s phone row with Angela Merkel, and Dominic Cummings’ incendiary phone briefing to the Spectator.  Perhaps the Taoiseach was spooked by the possibility of No Deal.  Or maybe came to envisage Johnson returning to the negotiating table after an election with a stronger mandate.  But for whatever reason, this is Ireland’s deal as much as Britain’s.

Anglo-Irish relations have been so strained recently that it is hard to imagine them turning turtle – with Varadkar pushing the EU consensus towards a short extension.  It would be the ultimate irony were Ireland to serve as the rescuer of Brexit.  We are sufficiently hopeful to deck out the Taoiseach in one of our Union Flag T-shirts this morning – meaning no offence, and hoping that all concerned take it in the spirit in which it is intended.