There are digital locks on the doors in the corridor where Neelie Kroes has her office. There is sensitive information here, about cartels suspected of price-fixing for instance. This week energy companies E.on and GDF Suez were fined 1.1 billion euros each. Microsoft, Heineken and Intel have suffered the same fate. On days like those, Kroes likes to greet visitors with the words: "I made some money for Europe today. You do realise this money will be refunded to the member states?"

For years, state aid had been a relic from the interventionist 1970s. Now, because of the crisis, more and more governments want to keep national companies afloat. While doing so, they're trying to bend the very rules they imposed themselves. Brussels has to weigh each request. Any disguised protectionism could lead to a new economic race between member states.

Kroes tries to be flexible, but when necessary she will go for a firm no. The German Commerzbank was forced to sell a large part of its activities. The Royal Bank of Scotland has to reorganise. Last year Kroes issued guidelines for governments to bail out the banks. Now she is drafting new guidelines for governments to get out of banking again in maximum five years.

These are crucial times for the European Union. When prime ministers and ministers fail to get past Kroes they tend to call her boss, Commission president José Manuel Barroso. That often leads to high drama. Kroes, however, can only talk about it in general terms. The European parliament is dragging its feet on giving Barroso a second term, and Kroes would like to stay in this job for another five years too. Better to be discreet.

Are we leaving the crisis behind us yet?

"We're not quite there yet. It's hard to say when we will be. The economy is all about emotions. There is no confidence yet in the banking and other sectors. People are cautious about investing. Credit is hard to get. People are not taking chances. They're on the fence. It's a vicious circle. If we're going to see a recovery, we first need a healthy banking sector. We're not there yet. The banks are often more concerned with themselves than with solving the real problem. They're just not that interested in the bigger picture."

Last week, while addressing bankers in London, you said that governments need to get out of banking because governments are not banks. The next day some newspapers wrote: Brussels Strangles The City.

"Facts and figures tell us that there is no money for a second round of bail-outs and that some banks are barely viable. You have to restructure them instead of putting them on life support."

So the crisis is not over?

"We're going to get more problems in many sectors. We've had the car industry and the German department stores. It's not over. But I'm optimistic by nature. What we need to do is to change our mindset."

Who does?

"Everybody. From the boardroom to the kitchen table. Unlike the US, Europe has a social safety net. That's a good thing. But it has meant that people are slower to realise what has happened. Look at Germany. They have an election coming up in September and they’re asking themselves: how many jobs can we afford to lose now?"

That puts you in a tough spot.

"It sure does. It was easy to explain why so much money needed to go to the banks: they are the lifeline of the economy. Even demonstrating Polish shipyard workers understood that. They angrily asked: if you're going to allow capital injections for banks why not allow them for our shipyards too? But now that if the car industry is getting state support aid too..."

That's impossible to explain?

"Those shipyards need to be made commercially viable. Just like the car factories. If we're just going to write cheques to keep overcapacity in place, we will miss the opportunity to make that industry healthy again, to give it a future. In that case the problem will get worse. It's different in the US where tough realism prevails, with big consequences."

Is that better?

"No."

Clearer?

"Yes."

In an interview with NRC Handelsblad on May 30, WTO boss Pascal Lamy warned against protectionism. The same week the Germans bailed out Opel.

"The Opel dossier has not passed for every country yet. Governments can't keep factories open just for the sake of it. There has to be a sound business plan as a basis. That's what I told Paris earlier, too."

You mean when president Sarkozy promised to help Peugeot and Renault on the condition that there would be no lay-offs in France?

"It's easy to fight protectionism in the general sense. Then everybody agrees with you: 'Of course we don't want to be protectionist. That's a bad thing.' But then the first case comes along, and suddenly it becomes very difficult."

Do you see a parallel with the 1930s: protectionism, political populism?

"If we're not careful, yes. That's why we need to be right on the ball. We need to explain to people that things would have been much worse if it wasn't for the euro and the internal market."

Will there be more Europe or less Europe when the crisis is over?

"There is, I think, no way back. The crisis is a unique opportunity to make progress. The question is are we going to seize that opportunity? There is a changing of the guard at the commission. There is uncertainty about the Lisbon Treaty, meaning the future relationship between governments, the European parliament and the Commission. That slows things down."

What do you like about your job?

"To be part of this crucial phase in the history of Europe."

What don't you like about it?

"Having to compromise."

Compromise on state aid?

"No, not as far as my decisions are concerned. I mean as a member of the commission."

Didn't you water down the state aid rules?

"No! The principles are still standing strong. I've had to be more flexible about implementing them temporarily. The weather is bad out there, so you have to make the framework more flexible or everything goes down the drain."

What's going to happen next with the banks?

"This will be the moment of truth. Things don't always move as fast as I would wish them to. Some banks will have to be restructured. We don't want to have another crisis on our hands in a few years’ time. My nightmare scenario is my granddaughter asking me one day: 'Did you really do all you could?' and that I would have to answer: 'Just a little bit.'"

You've had some fierce clashes with The Hague.

"It's part of the job. No one gets preferential treatment. Ever. [Dutch finance minister] Wouter Bos has some tough issues to deal with but they will not be resolved by waiting."

Do you want to stay on as commissioner?

"That's up to the Dutch government to decide."

But do you want to?

"Only if it is this portfolio, not another one."

Your new director-general is from the Netherlands. Is it possible to have two Dutch people in charge of the competition directorate-general?

"Can you show me where there is a rule that says this is not possible? I can't find where it says that the director-general and the commissioner have to be from two different countries."

Perhaps it's an unwritten rule.

"Barroso wants to return to the same position. So why not me?