Eurozone under pressure over Greek debt drama

The pressures on Greece over the next few days are pretty obvious.

Failure to strike a deal would leave both the Greek state and the Greek banking system staring bankruptcy in the face.

Money would run out, and imported goods would soon disappear.

And while the rest of the EU would offer humanitarian support, it would be extremely painful for all concerned.

But there are also pressures on the rest of the eurozone - less immediate perhaps, less obvious in some ways, but equally significant.

First of all there are the economic factors. The eurozone countries now hold the lion's share of Greece's huge sovereign debt.

They acquired it deliberately over the last few years from eurozone banks, as part of their plans to save the banking system.

And if you take debt held by the eurozone's bailout fund, and add bilateral loans to Greece from the eurozone countries, you get a total close to €200bn ($222bn; £144bn).

If Greece were to leave the euro, half of that would probably never be paid back. There is also an unquantifiable risk from contagion and other economic shocks.

There is no doubt that the eurozone has better defences than it did five years ago. But it is legitimate to argue that kicking Greece out would cost a lot more than keeping Greece in.

And what if Greece were able to absorb the immediate economic shocks, and then return to sustainable growth outside the euro with a new devalued currency?

That could over time become a temptation too far for other struggling eurozone economies.

Then there are political factors. And in the end, as it is worth repeating, this is about the politics of European integration.

There is a lot of talk of solidarity in the EU. Developments in Greece over the next few days will determine whether all the talk adds up to much.

Because the euro is not just an economic project; it is a political one. The single currency has become the most important symbol of the European Union.

That is why Eurosceptics are revelling in the prospect of Greece leaving the eurozone. They argue that it proves their point that the whole edifice is rotten.

And so leaders who believe in the European project have to decide whether they are prepared to take the risk of allowing a country to leave.

Sending the message that the eurozone is not "forever" runs the risk of reducing it to little more than an exchange rate mechanism.

And the next time a country gets into trouble, no-one will believe politicians who insist that all is well.

All this means the debate about Greece poses big questions for the eurozone's big political leaders: for the leaders of the EU institutions, for President Hollande in Paris, and - above all - for German Chancellor Angela Merkel.

She is now clearly "first among equals" in the EU, and one thing has been proven time and again during the eurozone crisis - it is Germany that gets to set the rules of the game.

One of Mrs Merkel's favourite phrases in recent years has been very simple: "If the euro fails, Europe fails."

But the EU faces multiple threats and challenges over the next few years - notably from a resurgent Russia to the east.

Anything that might suggest that Europe's resolve to help one of its own is weakening could set an uncomfortable precedent.

The United States clearly believes this is no time for the eurozone to contemplate allowing Greece to slip away.

And there are other security issues at play as well.

Efforts to deal with the migrant crisis in southern Europe would become far more complicated if Greece were to become semi-detached.

It comes back to that notion of solidarity, and where its limits lie.

Sometimes, none of this matters. Events take on a momentum of their own.

But all the main players have a lot to lose in this process. And that is one of the main reasons why, despite all the bad blood, a deal between Greece and its creditors is still possible.