The word 'historic' gets bandied about far too much. Historic this, historic that, you hear - normally about stuff you can't quite remember a few years later.
But today is a truly historic day. The day Britain wielded its veto at last. The day that British Prime Ministers have struggled to avoid ever since they turned their minds to joining the European 'project', in some form, during the 1950s. They day she was excluded from the inner core.
Unprecedented. Momentous. Defining. Symbolic. Historic. Choose your word. None of them will be big enough.
It's set Britain on the fast track to an outer ring of European states, along with perhaps Sweden and the Czech Republic. She will not be able to exercise much influence on the course of events from that position. All the hard-won gains of the past fifty years - in terms of Britain's voice in Europe - might now dribble away.
It's earned Westminster and Whitehall the enmity of France and Germany, who blame her 'Anglo-Saxon' economics for the whole mess in the first place. If we see fight after fight about the powers of the 'ins' and the 'outs', the inner core of 23 might well now insist on the UK leaving altogether.
And it's emboldened the Eurosceptics in the Conservative Party to call for full British withdrawal. They're not going to go away. They're going to get stronger and stronger, and louder and louder. They feel vindicated. They long to throw off the Coalition mantle, govern on their own and withdraw into an 'association' with the EEC, rather than full membership. They may well get their way - though only after fighting another General Election.
So what does today mean?
The failure to agree a treaty probably makes the breakup of the Euro, or at least the creation of a 'hard core' at its pinnacle, a little more likely. Bond markets will be unimpressed that the 27 could not stitch up a deal. Who is to say that 23 will do any better?
The UK Coalition government has probably had its span of days fixed - for remember that the great Victorian and Edwardian Liberal Party was originally shattered over great questions of peace and war in 1914-22. This is a set of principles that they have to hold on to. If they don't, their existence as a separate party is in doubt.
The British government has made its choice. For many years, at least since Edward Heath signed the Treaty of Accession in 1973 (above), the British have been uncertain. Were they atlanticists, citizens of the world, or were they truly Europeans? Now they have chosen. They are not Europeans.
The die is cast. An entirely new political landscape, even a new idea of what Britain is and is for, is being forged. No-one knows what it will look like - but it will be utterly different from the Britain we have known.
