Nicola Sturgeon, deputy first minister of Scotland, was in Brussels last night recording a video interview with EU Observer and declaring most definitely that an independent Scotland would stay out of the euro: 'Our attitude is to remain in the sterling currency.'

Which only proves that the Scottish government's deputy leader is a lot smarter than the British government's euro-loving deputy prime minister, Nick Clegg.

And I like to think it shows the Scottish Nationalists are paying attention to the advice I gave them in the Scottish Daily Mail last May --

Should Scotland become independent or not? I’m Irish, so I’m not the one to ask.

But if you want to know should Scotland become independent and join the euro, I am the one to ask -- exactly because I’m Irish. So, here’s the short answer: don’t do it.

Ireland’s independence has been destroyed by the European single currency. The lesson for Scotland from Ireland is that you cannot be both independent and in the euro. It can be one or the other, but not both. You can be a nation, or a province of the European Central Bank. One or the other, but not both.

Ireland’s independence has been destroyed because its politicians – their vanity fed by too many trips to swish meetings in Brussels with their ‘European partners,’ their constituents tempted by unearned money poured in from EU structural funds – let themselves be convinced that sovereignty really could be shared.

It can’t, of course. You can’t share your sovereignty any more than you can share your lungs. Yet in one treaty after another, Irish politicians led their people to hand over their sovereignty in return for everything going from Brussels, especially the euro.

Why especially the euro? Because Irish politicians and too many citizens raised in the pub-ballad version of Irish history thought this would be the final way to show Ireland was no longer some province of Britain, that it really was a nation once again.

More, joining the euro would show Ireland was a ‘European’ nation, as though embracing a currency run for the benefit of Germany and France would turn the Irish into a nation of Continental sophisticates. And the old master Britain would be ‘isolated,’ outside the euro. Perfect.

It was entirely a political decision. There was not one economic argument to be made in favour of joining the euro. Ireland’s most important trading partners then, and now, were Britain and the United States, and not any of the European states which were to form the single currency.

Surrendering the Irish currency, the punt, to the euro was just nationalist delusion. I hope that if Scotland votes to become independent it will not fall into the same delusion.

It would be foolish to chain the Scottish nation to the euro. That would just be changing the economic and monetary union called the UK for an economic and monetary union called the eurozone.

Because if you can’t control your currency, can’t influence your exchange rate, can’t set your interest rates, can’t control your monetary policy, or your fiscal policy – yes, the eurozone powers are now reaching into control the budgets of every member state – then you are not an independent country.

Right now there are EU officials – known to Irish civil servants as ‘the Germans,’ whatever nationality they are – with offices in what were once Irish government buildings, controlling Irish taxation and spending policy.

If an independent Scotland were to join the euro, ‘the Germans’ would soon set up in Edinburgh.

Yet I suspect the pro-independence movement in Scotland doesn’t realise how far the euro has moved towards fiscal and economic control of its member states. Listening to Scottish nationalists, they seem still back on the 1990s when the line was that joining the euro would just be a small part of economic sovereignty that could be passed over to Frankfurt.

That’s the line the Irish fell for. Will the Scots fall for it, too?

Maybe not, if they realise what happened next to Ireland. During the 1990s, when Ireland still had its own currency and independent economic and fiscal policy, it finally stopped its old high-tax and high-spending ways, and turned itself into a lean, business-oriented economy.

It attracted foreign direct investment. It had a young educated workforce and low labour and infrastructure costs. It had a low corporate tax rate that attracted the top American pharmaceutical and high-tech companies such as Intel to open vast factories in Ireland. Young graduates stopped emigrating to find work in Britain and America.

Ireland did, in fact, what I’d guess Scottish nationalists dream of doing in an independent Scotland. Scotland has lost its heavy industry. However Unionists may mock Ireland now, Ireland’s way out of the grim 1970s and 1980s is the way Scotland must take: high tech, high skill, low cost, low tax foreign direct investment industries.

Then Ireland in all its delusions joined the euro. Its Central Bank turned over control of Ireland’s interest rates to the European Central Bank.

And as this growing Ireland entered the first years of the new century, it found it was caught in a currency union which was setting its interest rates to suit the German economy.

Yet the German economy was flat-lining at just the moment Ireland was beginning to boom: so Berlin demanded and got historically low eurozone interest rates.

The Irish economy started to overheat. An independent central bank in an independent Ireland would have yanked up interest rates to cool things off.

Instead, the ECB kept eurozone interest rates at two percent. German people, caught in a stagnant economy and refusing to spend, put their euros into their bank deposit accounts. The German banks, looking for ways to make big profits, pumped the cash into Ireland’s banks, which were willing to feed the Irish property boom with this tsunami of German savings.

With this flood of euros, Irish labour costs rose. Infrastructure costs rose. Commercial rents rose. Suddenly high tech companies were shutting down: Dell computers moved 2,000 jobs to Poland.

In the old Europe of independent states, this could not have happened. But in a ‘Europe without frontiers,’ tens of billions of euros can slosh from one member state’s banking system to another, and the banking system in a small country such as Ireland – or Scotland – need no longer stay sober and depend on domestic savers for their cash.

Then, the disaster: Lehman’s, the global credit crisis, and Ireland thrown into the worst recession in the entire world. Property prices halved. And the banking system could not repay the billions it had borrowed.

An independent Ireland could have done the right thing, which was, let the banks tell their creditors that they had made bad investments in buying Irish bank bonds, and they were going to have to take a haircut. Or they could swap their lame bonds for shares in the banks: creditors into shareholders.

But the German-controlled ECB wasn’t having that. It blackmailed and arm-twisted the terrified Irish government into agreeing to guarantee all bank debt, even before the government had any idea how big the debt was: the ECB was determined to save German bond holders.

By a calculation from the Irish economist Morgan Kelly, taking over Irish bank debt will now push government debt to a final figure of £219bn. That is equal to debt of £105,000 per Irish worker. You will not be surprised to learn that Irish workers are emigrating again, and at a rate of 1,000 a week.

Now you know what happened in Ireland after it joined the euro. The only question remaining is: what happens next in Scotland – staying in the British union, joining the eurozone union, or becoming independent? Choice of just one, not two out of three.