Four years after the Lehman crisis, economic activity and employment in the OECD has not yet returned to its pre-crisis level. Unemployment is at postwar highs in every major European country apart from Germany and, while the U.S. jobless rate is now a little below its postwar record, it has been stuck above 8 percent for longer than at any time since the Great Depression. And in Britain, the long-term loss of output assumed by the government's latest budget forecasts implies, according to Goldman Sachs calculations, that the six months of the post-Lehman crisis did greater permanent damage to the country's productive capacity than the Great Depression or World War Two.

Now consider the response. In the U.S., the four years since Lehman have been dominated by economic debates among politicians, media commentators and business leaders on issues that are almost totally irrelevant to unemployment and the pace of economic recovery: how to reduce long-term budget deficits and whether to tweak the top rate of income tax from 36 percent to 39.6 percent. In Britain, the biggest economic controversy this year has been the extension of value added tax to hot pies. Europe's response to the deepest economic depression in living memory - and an even more alarming xenophobic nationalism that threatens the literal disintegration of the euro and the European Union - has been to debate the bureaucratic "modalities" of bank regulations, fiscal treaties and pension reforms in the next decade.

How to explain this insouciance in the face of the gravest threat to the Western world since the height of the Cold War?