There was some faux shock and surprise at the decision by Syriza's Alexis Tsipras to join in coalition with the right-wing independent Greek party, ANEL.

Sell out! Told you so! So much for lefty solidarity.

But no one should have been surprised. Syriza isn't a traditional party of the left, though there are left-wingers involved. It is a populist coalition, much closer to the SNP than an old-style, centralist communist party. Its message has been "end national humiliation" rather than expropriate the expropriators. It has an affinity with other nationalist parties to the extent that they agree Greece has become a "debt colony".

There is a profound sense of humiliation in Greece. They read in German and British newspapers about how they are all corrupt, lazy and ignorant and they find this offensive; just as Scots resent being dismissed as subsidy junkies by Tory MPs and London newspapers. They think they have paid a pretty heavy penalty for the past sins of a corrupt elite.

Imagine if, in Scotland, 55 per cent of young people were unemployed; the economy had collapsed by 20 per cent since 2010; and real incomes had fallen by 25 per cent. This has been the fruit of the Troika's austerity programme of "internal devaluation" that involved drastic wage cuts and public spending cuts. Things were supposed to have improved by now but they haven't.

You can't expect a democracy to put up with this indefinitely. Depression economics is no more acceptable in the EU today than it was in the United States in the 1930s. And anyway, it doesn't work. If the economy shrinks, debt just gets bigger, which is what has happened in Greece. It is a deflationary spiral.

What Syriza is calling for is essentially a Roosevelt-style New Deal. Yet Ed Miliband refused to say anything in support of Syriza, or indeed anything at all about their election victory, even though their anti-austerity posture, rhetoric aside, isn't that different from Labour's.

For all the talk of Trots against the Troika, Syriza's immediate programme is a minimum wage, free health care for the unemployed, reconnection of families cut off from the electricity grid and emergency food relief. It wants job creation and an end to tax evasion.

Syriza is pro-European and says it wants to run a balanced budget. Indeed, Greece is actually running a primary budget surplus at present, which means that - debt repayments excluded - it is actually paying its way in the world even on terms the Bundesbank would understand. The problem is the debt overhang of 175 per cent of GDP. It just gets bigger.

Countries such as Britain solved this problem by currency devaluation - 20 per cent in our case after the crash - which is a kind of default by stealth. Greece cannot do this because it is in the euro, so the only solution is for the debt burden to be shared. European governments have devoted trillions to bailing out the banks; Syriza is saying that it is time to bail out the people.

Anyway, in a democracy you have to give voters some hope, some prospect that things will improve but, after five years, they were getting worse. Greece has been in this state for almost as long as the duration of the Second World War and the economic impact has been very similar to a war.

And just as 60 years ago, there has to be a debt detente in Europe to start broader economic recovery. Germany should understand this very well because in 1953 it had half of its debts written off in the London Debt Agreement. Some politicians in Britain and America said that the Germans had only brought misfortune upon themselves by their aggression and should be kept in a state of pre-industrial penury as a punishment. Fortunately, that view did not prevail and debt relief provided the basis for the European economic boom of the 1950s and 60s.

Economic depressions are not natural events; they are always caused by policy failures. It is time for Europe to return to growth. But if nothing changes it might be in Greece's interests to restore its own currency and devalue. It wouldn't be the end of the world, but it would probably be the end of the euro.