Perhaps Greece will now default on its debts – less by design than accident – and will come tumbling out of the Euro.  And maybe, in turn, Grexit will trigger convulsions in other olive belt countries that will break up the single currency altogether.

Perhaps.  But the Euro project has to date survived the crises it has itself helped to create, and some British Euro-sceptics have underestimated both the drive of the EU elites for ever-closer union, and the fear of nationalism that spooks so many European voters.  After all, Syriza itself is not proposing that Greece leave the Euro.

So the most likely outcome of its near-outright victory is a fudge – as so often in the tale of the Euro before.  Syriza wants Greece to be given debt write-offs and more cash with which the minimum salary can be raised, plus higher pensions, new food and electricity coupons, home protection from repossession, access to free medical care and an end to tax on heating fuel.

How much of this package will it gain?  The answer will depend on how much of the programme Alex Tsipras, Syriza’s leader, and his party sticks to in the talks with the EU that will soon begin; whether his party is out-foxed or not by the EU’s leadership, particularly the Germans; whether it holds together; and what Greece’s other political parties do, since Syriza won’t have a workable Parliamentary majority.  Indeed, as I write it seems to have fallen just short of gaining one.

But although the moves of the game are obscure, its shape is clear.  At one end of the board be will Syriza and other Greek parties, clamouring for more money from Germany.  At the other will be the Alternative für Deutschland and others, asking why that country’s taxpayers should subsidise Greece’s fakelaki culture – its bribe-friendly civil servants and tax-dodging professionals.  In between will be Angela Merkel, who has already said that Greece must be found money, sorry, “solutions”.

And watching from the wings will be the voters and extremist parties in Europe’s other blighted economies – particularly Spain, who will be learning the lessons of Syriza’s breakthrough.

Yes, it’s roll up, roll up and play the Great Euro Game.  First, drive a nation to destitution (a quarter of Greece’s workforce is unemployed, average pensions have fallen by 40 per cent in value and hundreds of thousands of its people are on the breadline).  Second, ask the voters of another to bale it out.  Third, see the people of the first country put Marxists at the top of the ballot and Nazis third.  Fourth, risk driving the voters of the second country to extremism, too.  And finally: repeat across a whole continent, light the blue touch paper, and retire – if you can find a safe place to retire to.

All praise and honour to the weird combination of James Goldsmith, John Major, Gordon Brown, William Hague and Ed Balls that helped keep us out of it.  David Cameron can follow in their footsteps, if he returns to Downing Street in May, by taking Liam Fox’s advice – and pushing for one of the two logical solutions: exit from the Euro by either Germany or Greece and its companions; or else complete Eurozone political, economic and monetary union.

That would mean a new treaty.  And that in turn would mean an opportunity for Cameron to help create a new Europe-wide, non-EU, free market-based arrangement for both Britain and other non-Eurozone nations.