There’s a bit of a lull in the news from Europe, but the underlying situation is as terrible as ever. Greece is experiencing a slump worse than the Great Depression, and nothing happening now offers hope of recovery. Spain has been hailed as a success story, because its economy is finally growing — but it still has 22 percent unemployment. And there is an arc of stagnation across the continent’s top: Finland is experiencing a depression comparable to that in southern Europe, and Denmark and the Netherlands are also doing very badly.

How did things go so wrong? The answer is that this is what happens when self-indulgent politicians ignore arithmetic and the lessons of history. And no, I’m not talking about leftists in Greece or elsewhere; I’m talking about ultra-respectable men in Berlin, Paris, and Brussels, who have spent a quarter-century trying to run Europe on the basis of fantasy economics.

To someone who didn’t know much economics, or chose to ignore awkward questions, establishing a unified European currency sounded like a great idea. It would make doing business across national borders easier, while serving as a powerful symbol of unity. Who could have foreseen the huge problems the euro would eventually cause?

Actually, lots of people. In January 2010 two European economists published an article titled “It Can’t Happen, It’s a Bad Idea, It Won’t Last,” mocking American economists who had warned that the euro would cause big problems. As it turned out, the article was an accidental classic: at the very moment it was being written, all those dire warnings were in the process of being vindicated. And the article’s intended hall of shame — the long list of economists it cites for wrongheaded pessimism — has instead become a sort of honor roll, a who’s who of those who got it more or less right.