This is not the deal that the European Union would have wanted on day one.
It is, they think, peppered with compromises and irritations, but the European nations believe it gives them something they desperately wanted – a sense of unity.
The group of 27 leaders took relatively little time to sign off on the deal at the start of the summit in Brussels.
All gave it a warm welcome – the Dutch leader Mark Rutte told me he felt like rejoicing; Ireland’s Leo Varadkar acclaimed the deal as proof of how the EU can pull together.
But there was greater meaning behind those words. The EU thinks it is calling Britain’s bluff by delivering a Brexit agreement that, pretty broadly, delivers most of the benefits of the backstop without actually being a backstop.
So when Michel Barnier, Jean-Claude Juncker and Donald Tusk stood up to laud the deal, they weren’t so much talking to Europe, as to British politicians. Their message: “We have compromised to get this deal – if it fails now, it’s your fault.”
Why? Well, according to well-placed sources, Mr Juncker, the European Commission President, received assurances from Boris Johnson that a deal would pass through the House of Commons.
Mr Juncker is standing down from his job in six weeks’ time, and is keen that his reign finishes on the high point of diplomatic triumph rather than either an extension or a no-deal Brexit.
He believes, emphatically, that no-deal would be disastrous for the European economy.
Perhaps that’s why he was so forthright in announcing that there would be no extension beyond the end of this month. That’s what he wants – a deal, now.
His gambit is that, by raising the spectre of a deadline in a fortnight, MPs might rail in behind the deal.
But the trouble is that the decision about whether to give an extension is not up to him – if this deal fails in parliament, and the government is forced to ask for more time, that decision will fall entirely on to the shoulders of the other European leaders.
Mr Juncker may be able to cajole, persuade and influence, but he doesn’t have a vote.
So Brussels is now planning two paths. If the deal passes through the House of Commons, then expect a meeting of EU ambassadors on Sunday, the Brexit steering group of MEPs on Monday, the parliament’s constitutional affairs committee on Tuesday before finally being ratified by the European Parliament, probably on Thursday.
But what if it doesn’t succeed in Westminster? We may still get the meeting of ambassadors on Sunday, but after that we are into the realm of the Benn Act, and an extension.
There are plenty of EU countries who are wary, and weary. They’re tired of the constant, sapping debates about a country that wants to leave.
“You have become the country that is on the edge of the garden, with its back to the fence,” one diplomat told me. “We keep talking to you, but it’s becoming awkward. You don’t want to be here any more. We’re all wondering whether it would be better if you were actually on the other side of the fence – still talking to us, but outside the garden.”
But would they refuse an extension? Almost certainly not.
I spoke to representatives from a range of EU countries and none suggested they would even consider vetoing an extension. When push comes to shove, they still think it’s too early to embrace a no-deal Brexit.
Some, convinced that the deal offered here cannot be changed, believe the extension should be short – a chance for an election, say, or a change of heart.
Others are talking about something much longer, lasting into summer 2020 and beyond – a chance for a complete rethink. But all, of course, wait to see if an extension is even required.
“It is not up to us now – it is up to Westminster,” was a refrain from more than one diplomat. In Brussels, they are now watching events in parliament, wondering whether this chapter of Brexit is coming to a close, or simply heading for another meander.